Before you engage a plumber, you should also look at hourly rates. Get a couple of estimates for a task by calling around. Before the plumber starts working, make sure he is prepared to sign an estimate and provide you with a price guarantee. Find out if the plumber will ask you to travel to and from your job, as well as how they will calculate that time and provide it to you. While providing you with exact pricing may be difficult, you should stay away from any plumber who cannot provide you with a detailed explanation of how you will be billed along with an estimate of the cost.