I would take mostly cash, and have a cc as a backup. Generally, I can get a better deal from a seller if I tell them I'm paying cash and this is what I can offer. This also gives me the opportunity to go back to the same seller later, and buy another card at perhaps a better price, again. If I pay with a cc, I burn that bridge as cc's typically give us extended spending power and the seller knows I really don't need to have deal cut to buy a card. Cash also help to keep me in a budget.
