Below is every merchant who can sell blueprints, and every BP they have a chance to sell.
Vinelton is the Ancient Grove vendor. You can see that he upgrades from relic blueprints to helmet ones at level 50.
The non-relic BPs he has a chance to sell are really nothing to rave about, unfortunately. It’s not bad if you’re missing a few of them.
Vinelton
records/creatures/npcs/merchants/merchanttbl_c101.dbr
records/items/loottables/blueprints/lt_blueprints_d01_head_ancientgrove.dbr
Level 1:
records/items/loottables/blueprints/tdyn_blueprints_b02.dbr
Blueprint: Relic - Bladedancer's Talisman
Blueprint: Relic - Marauder's Talisman
Blueprint: Relic - Terror
Blueprint: Relic - Torment
Blueprint: Relic - Slaughter
Blueprint: Relic - Juggernaut
Blueprint: Relic - Savage
Blueprint: Relic - Deathchill
Blueprint: Relic - Haunt
Blueprint: Relic - Conflagration
Blueprint: Relic - Arbiter
Blueprint: Relic - Fortress
Blueprint: Relic - Glacier
Blueprint: Relic - Squall
Blueprint: Relic - Inferno
Blueprint: Relic - Corruption
Blueprint: Relic - Sanctuary
Blueprint: Relic - Guile
Blueprint: Relic - Rampage
Level 50:
records/items/loottables/blueprints/tdyn_blueprints_d01_head.dbr
Blueprint: Crown of the Winter King
Blueprint: Trozan's Hat
Blueprint: Markovian's Visor
Blueprint: Ulzuin's Headguard
Blueprint: Demonslayer's Hat
Blueprint: Clairvoyant's Hat
Blueprint: Iskandra's Hood
Blueprint: Ultos' Hood
Blueprint: Hood of Dreeg
Blueprint: Deathmarked Hood
Blueprint: Beastcaller's Cowl
Blueprint: Mask of the Harbinger
Blueprint: Maw of Despair
Blueprint: Dread-Mask of Gurgoth
Blueprint: Whisperer of Secrets
Blueprint: Abyssal Mask
Blueprint: Circlet of the Great Serpent
Blueprint: Mask of Infernal Truth
Blueprint: Faceguard of Justice
Blueprint: Light's Defender Helm
Blueprint: Visage of the Black Flame
Blueprint: Cowl of the Venomblade
Blueprint: Valdun's Hat
Blueprint: Bloodrager's Cowl
Blueprint: Warborn Visor
Blueprint: Infernal Knight's Faceguard
records/items/loottables/blueprints/lt_blueprints_ancientgrovevendor2.dbr
Level 1:
records/items/loottables/blueprints/tdyn_blueprints_ancientgrovevendor2.dbr
Recipe: Ugdenjuice
Recipe: Ugdensalve
Recipe: Vilescar Ointment
Recipe: Elixir of the Dranghoul
Recipe: Elixir of Mogdrogen
records/items/loottables/blueprints/lt_blueprints_ancientgrovevendor.dbr
Level 1:
records/items/loottables/blueprints/tdyn_blueprints_ancientgrovevendor.dbr
Blueprint: Eye of Dominion
Blueprint: Codex of Eternal Storms
Blueprint: Shard of Beronath
Blueprint: Prismatic Diamond
Blueprint: Empowered Skyshard Spellblade
Blueprint: Empowered Malformed Effigy
Blueprint: Badge of Mastery
Blueprint: Mark of Divinity
Blueprint: Mark of Fierce Resolve
Blueprint: Empowered Tempest Sigil
Blueprint: Ulda'Jax
Blueprint: Empowered Spellfire Wand
Blueprint: Ruby of Elemental Balance
Blueprint: Sapphire of Elemental Balance
Blueprint: Maiven's Lens
Blueprint: Vortex Stone
Blueprint: Lapis Mantichora
Blueprint: Empowered Plaguemancer's Amulet
Blueprint: Empowered Essence of Beronath
Blueprint: Starfury Emerald
Blueprint: Essence of the Grim Dawn
Blueprint: Herald of the Apocalypse
Blueprint: Pestilence of Dreeg
Blueprint: Damnation
Blueprint: Raka'Jax
Blueprint: Arcanum Sigillis
Blueprint: Empowered Black Grimoire of Og'Napesh
Blueprint: Olexra's Chill
Blueprint: Leviathan
Blueprint: Beronath, Reforged
Blueprint: Herald of Blazing Ends
Blueprint: Siegebreaker
Blueprint: Basilisk Claw
Hyram, the Malmouth rare goods vendor that you unlock via a sidequest has a chance to sell the following. Note the BP inventory change at level 35. (It’s not likely many people get there earlier…)
Hyram
records/creatures/npcs/merchants/merchanttbl_a101.dbr
records/items/loottables/blueprints/lt_blueprints_crelicsvendor.dbr
Level 1:
records/items/loottables/gearaccessories/tdyn_waist_a01.dbr
Cloth Strap
Woven Cord
Hide Sash
Leather Belt
Level 15:
records/items/loottables/blueprints/tdyn_blueprints_brelicsvendor.dbr
Blueprint: Relic - Sacrifice
Blueprint: Relic - Zeal
Blueprint: Relic - Terror
Blueprint: Relic - Torment
Blueprint: Relic - Slaughter
Blueprint: Relic - Juggernaut
Blueprint: Relic - Savage
Blueprint: Relic - Deathchill
Blueprint: Relic - Haunt
Blueprint: Relic - Conflagration
Blueprint: Relic - Arbiter
Blueprint: Relic - Fortress
Blueprint: Relic - Glacier
Blueprint: Relic - Squall
Blueprint: Relic - Inferno
Blueprint: Relic - Corruption
Blueprint: Relic - Sanctuary
Blueprint: Relic - Guile
Blueprint: Relic - Rampage
Blueprint: Relic - Bladedancer's Talisman
Blueprint: Relic - Ancestor
Blueprint: Relic - Blight
Blueprint: Relic - Desolation
Blueprint: Relic - Marauder's Talisman
Level 35:
records/items/loottables/blueprints/tdyn_blueprints_crelicsvendor.dbr
Blueprint: Relic - Zeal
Blueprint: Relic - Desolation
Blueprint: Relic - Deathchill
Blueprint: Relic - Sacrifice
Blueprint: Relic - Bladedancer's Talisman
Blueprint: Relic - Marauder's Talisman
Blueprint: Relic - Blight
Blueprint: Relic - Ancestor
Blueprint: Relic - Conflagration
Blueprint: Relic - Savage
Blueprint: Relic - Arbiter
Blueprint: Relic - Fortress
Blueprint: Relic - Slaughter
Blueprint: Relic - Juggernaut
Blueprint: Relic - Terror
Blueprint: Relic - Torment
Blueprint: Relic - Haunt
Benevald has the Skeleton Key guaranteed, and an assortment of BPs starting from level 10 with a pretty low chance.
Benevald
records/creatures/npcs/merchants/merchanttbl_b01.dbr
records/items/loottables/blueprints/lt_blueprints_secretrovervendor.dbr
Level 1:
records/items/loottables/blueprints/tdyn_blueprints_secretrovervendor.dbr
Blueprint: Skeleton Key
records/items/loottables/blueprints/lt_blueprints_b04.dbr
Level 1:
records/items/loottables/gearaccessories/tdyn_waist_a01.dbr
Cloth Strap
Woven Cord
Hide Sash
Leather Belt
Level 10:
records/items/loottables/blueprints/tdyn_blueprints_b04.dbr
Blueprint: Glyphed Tome
Blueprint: Hand Mortar
Blueprint: Shrapnel Gun
Blueprint: Shrapnel Pistol
Blueprint: Adept's Morningstar
Blueprint: Brutal Carver
Blueprint: Adept's Flanged Mace
Blueprint: Adept's Boots
Blueprint: Adept's Greaves
Blueprint: Honed Broadsword
Blueprint: Honed Conqueror
Blueprint: Adept's Scepter
Blueprint: Master's Scepter
Blueprint: Flamesilk Sash
Blueprint: Frostguard Girdle
Blueprint: Omen
Blueprint: Witchstalker
Blueprint: Bounty Hunter's Girdle
Blueprint: Shockweave Sash
Blueprint: Warmonger's Belt
Blueprint: Wraithbone Sash
Blueprint: Tremor
Blueprint: The Eye
Blueprint: Spellfire Wand
Blueprint: Maiven's Lens
Blueprint: Explorer's Trousers
Blueprint: Explorer's Tunic
Blueprint: Guardsman's Breastplate
Blueprint: Guardsman's Defender
Blueprint: Storm's Edge
Blueprint: Brutal Decapitator
Blueprint: Frontloading Rifle
Blueprint: Adept's Spellblade
Blueprint: Adept's Dagger
Blueprint: Sovereign Shield
Blueprint: Siege Shield
Blueprint: Adept's Grips
Blueprint: Adept's Gloves
Blueprint: Squire's Greaves
Blueprint: Squire's Boots
Blueprint: Adept's Circlet
Blueprint: Adept's Hood
Blueprint: Squire's Handguards
Blueprint: Squire's Gauntlets
Blueprint: Ranger's Casque
Blueprint: Ranger's Helm
Blueprint: Adept's Wand
Blueprint: Master's Spellblade
Blueprint: Occult Skull
Blueprint: Occult Effigy
Blueprint: Glyphed Spellbook
Level 50:
records/items/loottables/blueprints/tdyn_blueprints_b04b.dbr
Blueprint: Sapphire of Elemental Balance
Blueprint: Ulda'Jax
Blueprint: Empowered Spellfire Wand
Blueprint: Empowered Skyshard Spellblade
Blueprint: Callidor's Vestments
Blueprint: Myrmidon Visor
Blueprint: Shrapnel Gun
Blueprint: Master's Spellblade
Blueprint: Sovereign Shield
Blueprint: Brutal Decapitator
Blueprint: Unholy Visage of the Covenant
Blueprint: Flame Keeper's Jacket
Blueprint: Master's Scepter
Blueprint: Cowl of the Blind Assassin
Blueprint: Glyphed Tome
Blueprint: Honed Conqueror
Blueprint: Flamesilk Sash
Blueprint: Frostguard Girdle
Blueprint: Warmonger's Belt
Blueprint: Wraithbone Sash
Blueprint: Shrapnel Pistol
Blueprint: Adept's Flanged Mace
Blueprint: Occult Effigy
Blueprint: Empowered Chthonian Thread Sash
Blueprint: Equilibrium Sash
Blueprint: Blazethread Sash
Blueprint: Cowl of Mogdrogen
Blueprint: Mark of Fierce Resolve
Blueprint: Empowered Essence of Beronath
Blueprint: Empowered Plaguemancer's Amulet
Blueprint: Lapis Mantichora
Blueprint: Ruby of Elemental Balance
Blueprint: Empowered Tempest Sigil
Blueprint: Empowered Malformed Effigy
Blueprint: Empowered Black Grimoire of Og'Napesh
Level 86:
records/items/loottables/blueprints/tdyn_blueprints_b04c.dbr
Blueprint: Mythical Volcanum
Blueprint: Sanguinus
Blueprint: Mythical Blessed Torch
Blueprint: Bloodspill Cleaver
Blueprint: Mythical Sanctus Crest
Blueprint: Mythical Aldur's Inquisition
Blueprint: Mythical Duelist's Sabre
Blueprint: Mythical Widow's Sting
Blueprint: Mythical Sapphire of Elemental Balance
Blueprint: Mythical Shard of Command
Blueprint: Mythical Doomsaw of Gluttony
Blueprint: Mythical Burrwitch Peacekeeper
Blueprint: Mythical Hellmaw Shotgun
Blueprint: Mythical Dawnguard Helm
Blueprint: Mythical Flame Keeper's Jacket
Blueprint: Mythical Combat Medic's Mark
Blueprint: Mythical Amarastan Sigil
Blueprint: Rime-Rotten Wand
Blueprint: Deathborne Scepter
Blueprint: Mythical Amarastan Pauldrons
Blueprint: Mythical Nighthunter's Chestguard
Blueprint: Mythical Quickdraw Gloves
Blueprint: Mythical Spellweave Legwraps
Blueprint: Mythical Sharpshooter's Glass Eye
Blueprint: Mythical Unholy Visage of the Covenant
Blueprint: Mythical Doomforged Breastplate
Blueprint: Mythical Cowl of the Blind Assassin
Blueprint: Mythical Rifthound Leather Boots
Blueprint: Mythical Soul's Touch
Blueprint: Cosmic Torrent
Blueprint: Intrepid Warboots
Blueprint: Stoneplate Greaves
Blueprint: Stormherald's Visage
Blueprint: Mythical Bounty Hunter's Shoulderguard
Blueprint: Dreadwalker Cowl
Blueprint: Luminari Hat
Blueprint: Mythical Magelord's Greaves
Blueprint: Stormsurge Pistol
Blueprint: Flamewarder Rifle
Blueprint: Stonewall Defender
Blueprint: Gutcrush Warmaul
Blueprint: Rageflame Spellblade
Blueprint: Mythical Ruby of Elemental Balance
Blueprint: Mythical Banshee's Misery
Blueprint: Mythical Lichguard
Blueprint: Mythical Tainted Blade of Nera'Val
Blueprint: Mythical Hellrune Carver
Blueprint: Mythical Wrathmourne
Blueprint: Mythical Goliath Signet
Blueprint: Nimble Crest
Blueprint: Mythical Cowl of Mogdrogen
Blueprint: Mythical Myrmidon Visor
Blueprint: Mythical Callidor's Vestments
Blueprint: Stoneplate Waistguard
Blueprint: Puppetmaster Links
Blueprint: Trollheart Waistguard
Blueprint: Watcher Crest
Blueprint: Runefather's Gem
Blueprint: Mythical Serenity Stone
Blueprint: Smoldering Effigy
Blueprint: Spellshock Tome
Blueprint: Mythical Amulet of Scorched Earth
Blueprint: The Dissenter
Blueprint: Mythical Chains of Anguish
Blueprint: Mythical Alchemist's Belt
Marris Kas is the Torment vendor.
Marris Kas
records/items/loottables/blueprints/lt_blueprints_stepsoftormentvendor.dbr
Level 1:
records/items/loottables/blueprints/tdyn_blueprints_stepsoftormentvendor.dbr
Recipe: Bloodfang Oil
Recipe: Arcanum Oil
Recipe: Hoarfrost Ointment
Recipe: Deathwhisper Ointment
Recipe: Lifestealer Oil
Recipe: Venomfang Oil
Recipe: Spiritbane Ointment
Recipe: Bloodbound Ointment
Blueprint: Relic - Glacier
Blueprint: Relic - Squall
Blueprint: Relic - Inferno
Blueprint: Relic - Corruption
Blueprint: Relic - Sanctuary
Blueprint: Relic - Guile
Blueprint: Relic - Rampage
Karros Adal is in Bastion of Chaos:
Karros Adal
records/creatures/npcs/merchants/merchanttbl_c02.dbr
records/items/loottables/blueprints/lt_blueprints_bastionofchaosvendor.dbr
Level 1:
records/items/loottables/blueprints/tdyn_blueprints_bastionofchaosvendor.dbr
Recipe: Elixir of the Aether
Recipe: Elixir of the Ancients
Recipe: Stormshroud Ointment
Recipe: Venomguard Ointment
Recipe: Elixir of the Void
Recipe: Elixir of the Hunt
Recipe: Frostshroud Ointment
Recipe: Flamedrinker Ointment
Blueprint: Relic - Glacier
Blueprint: Relic - Squall
Blueprint: Relic - Inferno
Blueprint: Relic - Corruption
Blueprint: Relic - Sanctuary
Blueprint: Relic - Guile
Blueprint: Relic - Rampage
Agarrad is the Port Valbury merchant:
Agarrad
records/creatures/npcs/merchants/merchanttbl_c03.dbr
records/items/loottables/blueprints/lt_blueprints_portvalburyvendor.dbr
Level 1:
records/items/loottables/blueprints/tdyn_blueprints_portvalburyvendor.dbr
Blueprint: Relic - Deathchill
Blueprint: Relic - Bladedancer's Talisman
Recipe: Elixir of the Aether
Recipe: Elixir of the Ancients
Recipe: Stormshroud Ointment
Recipe: Venomguard Ointment
Blueprint: Relic - Conflagration
Blueprint: Relic - Savage
Recipe: Elixir of the Void
Recipe: Elixir of the Hunt
Recipe: Frostshroud Ointment
Recipe: Flamedrinker Ointment
Blueprint: Relic - Marauder's Talisman
Blueprint: Relic - Arbiter
Blueprint: Relic - Fortress
Blueprint: Relic - Slaughter
Blueprint: Relic - Juggernaut
Blueprint: Relic - Terror
Blueprint: Relic - Torment
Blueprint: Relic - Haunt