After you've haggled over the price, you can pay for your one-of-a-kind treasure with your credit card.
Relying on cash-only customers saw sales plummet as much as 60 percent, says veteran vendor Diana Ryan of Antioch, Ill. "A lot of lookers and browsers would stumble upon something they couldn't live without, but didn't have cash, and we don't accept checks because they bounce more often than not."
Credit cards give flea market vendors the peace of mind that personal checks can't. "Once we receive an authentication code, I know we'll be paid. That's not the case with checks," says Ryan.