Having plumbing work done, whether it's for your home or business, can be incredibly expensive. That's why it's vital for you to ask a plumbing service the right kind of questions before you hire them. You want to do as much due diligence on your part as possible to get a professional who will not only do quality work but also charge you a fair price for it.
Sometimes a faucet leak can be stopped by replacing the rubber washer at the end of a faucet stem or cartridge. This is a more common repair on older fixtures when things were built to last and designed to be able to be maintained. Other times the whole stem or cartridge needs replacement or the bibb seat deeper back into the fixture needs replacement. That leads to matching up the right components and often times making a trip to the hardware store or plumbing supply house necessary due to the many varieties, makes and models of faucets. My advice is to make sure your Plumber has faucet repair kit on their truck before having them come out to assess the issue.