Use the following trick with any merchant to get unlimited caps and supplies. Start with between 2,000 to 3,000 caps two of the same weapon, one in very good condition and one in very bad condition. Go to any merchant and purchase everything desired from him or her. Then, sell the merchant both of the weapons. Buy back the cheap one and sell it back. Every other time you do this, the merchant will give the weapon in good condition for the price of the other weapon. Sell it back, thus obtaining three times what you paid for it. Repeat this until you have your caps back and everything the merchant owns. Note: On very rare occasions the game may freeze while doing this; make sure to save it.