Installing plumbing in Dallas can be costly, depending on several things. Chief among them is the kind of project you're doing—plumbing for new construction, for example, or extensive remodeling, will usually cost more because there's a lot more to do. And then there's the matter of connection to the main water supply and sewer line. And then the pipes and fixtures; if you use good materials, you'll pay a premium, of course, but at least you won't have to worry about them for a long time. And then there's labor, and pretty much every plumber you talk to around here will say that Dallas has a strong economy, which can drive that up too. At the end of the day, however, there's a lot to be said for using a licensed, insured plumber who does good work and knows what the local codes are.