Most leaks are fixed with a wrench and some inexpensive replacement parts. New washers, O-rings, and stem cartridges run from $4 to $12, though some for fancy European faucets can cost four times more. If repairs are never-ending or debris from your pipes is lodged inside the faucet, spring for a whole new setup. New bathroom-sink faucets start at $25 and kitchen models at $50; double that for more cutting-edge styles and fancy finishes. New faucets should last 15 to 20 years, says Thomas Annunziata of Park Slope Plumbing Supply, in Brooklyn, New York. "But the inside's what counts," he says. He recommends a brass stem and warns against short-lived plastic parts.