Why do some pool companies charge more than others?

A pool company should charge you for the work that they do. Any pool will require some design, ordering/shipping, installation, and some landscaping as well. Your pool company should be able to help you in each stage of the project. Some pool companies, like Sunnyview, have the expert staff to see the project from start to finish. Other pool companies, who have less expertise, will have to hire sub-contractors to conduct some (or even most) of the work for them. The more work that gets sub-contracted out, the more your pool will cost.