Fallout – Can you tip brahmin in New Vegas

It's a glitch which allows you to -- under certain circumstances -- purchase weapons or armor from a shopkeeper, then sell them back for more than you paid for them, and to continuously loop that process, thereby giving you anything you want from the shop, as well as all the shopkeeper's caps, essentially for free.

This YouTube video demonstrates it on PC, and I've used it successfully in both Fallout 3 and Fallout New Vegas (already!). By the end of my last Fallout 3 run, I had over six figures in caps. Also, for a guy with less than an hour into New Vegas, I think I'm doing OK financially -- almost 800 caps.

The trick to it is having in your inventory a weapon or piece of clothing/armor which the shopkeeper sells, preferably at a lower repair value. Sell it to him, and commit the transaction. Buy it back and commit. Lather, rinse, repeat. It may take two or three repeats before you start buying it at its original value but selling it as 100% repaired.

I've made this community wiki so that more people can edit it and we can simply have one definitive answer. In doing so, I've also incorporated answers not only from what I've found via gameplay and The Vault, but also the other answers which are on this question as well.

• Sarah Weintraub: Various Vault Jumpsuits, but not armored ones nor utility suits.
• Festus: Sunset Sarsaparilla Star Bottle Caps (sort of -- with 50, he, sort of, gives you the "reward" of hearing the history of Sunset Sarsaparilla and a quest for the "real" reward.)
• Jane (Lucky 38): Snow Globes (the spiritual successors of Bobbleheads from Fallout 3, but do not grant any bonuses)
• Raquel (Boomers): Missiles (thank you Brian Schkerke)
• Jack (Boomers): Scrap Metal (thank you Douglas Leeder)
• Julie Farkas: Fixer, RadAway, Med-X
• Decanus Severus: NCR Dog Tags
• Quartermaster Mayes: NCR Dog Tags
• Private Sexton: Legion Ears
• Lindsay (Boomers): Mr. Cuddles (unique item)
• Ruby Nash: Radscorpion poison glands (traded for Ruby's Casserole)
• Isaac: 100 scrap metal, tin cans, bent tin cans, pots, coffee pots, metal cooking pans, metal cooking pots and/or irons
• Jas Wilkins: 1 deathclaw egg
• Children near Nellis Hangars: Rocket Souvenirs (though you only get Boomer fame, no caps nor other rewards)
• First Sergeant Astor: Irradiated NCR Dog Tags