Let the buyer beware.
Prov. Cliché When you buy something, you must take precautions against being cheated, because you cannot trust merchants to be honest about what they sell. Let the buyer beware when shopping for a used car. Several of the lamps among those Max offered for sale were broken. "If a customer isn't smart enough to try a lamp before he buys it, that's his problem," Max argued. "Let the buyer beware."