Adding A/C

I have a Fleetwood 2003 Mesa. I want to add a/c but I am getting pricing all over the place. I called the dealer I bought the trailer from and they want $1000 I then call camping world and they want $700 I am looking at the Colemen Mach series and both quoted the same unit. Is the trailer pre-wired already for a/c? has anybody ran into this type of problem? is it just a dealer being a dealer on the price? is camping world a good place to go to have work done? all I know is that I need some air (currently in Utah its 100+) before I go next week again. Please help!!!!!!!!!!!!!!!!!!!!!!!!1
RE: Adding A/C

thank you so much for the reply. This was the first time I have used this web site and I will be back. I will let you all know how it went. Off I go to finally get the A/C. YAAAAAAAAAAAAAA