There are a lot of variable that go into a pool install. You have to know how big you want your pool to be. Average size to you, might mean a bigger size to someone else. If you could get the exact dimensions that you want, that would be great. Also, what kind of materials are you going to you use in the pool? http://www.whittiervillagepools.com
It all depends on the area you are in. I have a feeling it will be more expensive if you are in a denser part of the city. It would take them more time to build, remove materials, and bring in building materials. The best thing to do would be to get a handful of quotes from companies and compare that way.
Michael Foster http://www.cvilleaquatics.com/pools_renovations.htm