Bomb: Yes
Remote Bomb: Yes
Dud?: No
Stun Grenade: Yes
What's Known as Strategy: Yes
Potion (S): Yes
Potion (L): No
Aegis Field: No
Armored Mode: Yes
Poison Mist: Yes
Rex Claw: Yes
Rusty Metal: Yes
Rapid Fire: Yes
Banana: Yes
Gunflame: Yes
DI Gunflame: No
Tyrant Rage: No
Chemical Love: No
Antidepressant Scale: No
Stun Edge: Yes
SE Charge Attack: No
Sacred Edge: No
Great Yamada Attack: No
Emerald Rain: No
Drill Special: No
Drunkard Shade: No
Hammer: Yes
Meteor: No
Poison: Yes
Oil: Yes
Black Hole: Yes
Tsuyoshi-shiki Ten'i: No
Dark Angel: No
Secret Garden: No
Crosswise Heel: No
Trishula: No
Ride the Lightning: No
Maximum Fortissimo: No
DI Volcanic Viper: No
Sickle Storm: No
T Potion (S): Yes
T Potion (L): No
Anti-Melee Rod: Yes
Anti-Armor Rod: No
Anti-Raider Rod: Yes
Healing Rod: Yes
P Drive: Yes
S Drive: Yes
Battery Rod: No
Scarecrow: Yes
Exciter: Yes
Purify the Door: No
Berserker Drink: Yes
I-ai Stance: No
Flaming Curtain: Yes
Cursed Rod: Yes
Calvados Bomb: No
Blessing of the Gale: No

Leather Jacket: Yes
Plated Armor: Yes
Chainmail: Yes
Heat Resistant Clothes: Yes
Kamikaze Boots: No
Winglet: Yes
Maiden's Shoes: Yes
Sharkhide Rubber Suit: Yes
Lead Bracelet: Yes
Jade Green Guitar: Yes
Lexicon of the All-Seeing Eye: Yes
Earrings of Rage: Yes
Buckle of Freedom: No
Buckle of Hope: No
Gentleman's Monocle: Yes
Dandy Man's Sunglasses: No
Izuna's Scabbard: Yes
Heat Gauntlets: Yes
Thunderseal: Yes
Fireseal: Yes
Wings of Shadow: No
Hustler's Shoes: Yes
Golden Armament: No
Cat Marked Pumps: Yes
Crimson Cape: No
Teleportation: Yes
Stun Emblem: Yes
GEAR Cells: Yes
Amulet of Hell's Flames: Yes
Warrior's Breath: Yes
Headband of Attention: Yes
Bracelet of Fighting Spirit: Yes
Crowned Ring: Yes
Portable Gramophone: Yes
Corundum's Shield: Yes
Guide to Healthy Living: Yes
Metal Bat: Yes
Bracelet of Calling: Yes
Historical Shoes: Yes
The Seventh Ring: Yes
Helm of the Dragonhorn: Yes
Warrior's Bangle: Yes
Glimmering Bangle: No
Poisonous Bangle: No
Wolf's Scarf: Yes
Rosario of Oath: No
Teacup: Yes
Divine Hammer: No
Electric Protector: Yes
Red Tricorne: Yes
Double-Edged Blade: Yes
Swordsman's Gauntlet: Yes
Thundergod's Raiment: No
Lion's Drawn Sword: No
Giant Tortoise Shell: Yes

List of stages where you can acquire un-buyable items.
I'll do that when I'll be done clearing all of them.