I made a list of the major appliance I needed and made one big order to Palomino RV parts in Michigan.
All the stuff arrived in two weeks on a double pallet with very cheap shipping. I saved 30% over the best prices I found from CW or PPL.
Here's the post that put me onto Palomino. I bought the stuff a couple of years ago so I don't know if they are still able to provide the prices they had back then. The only restriction is you need to know exactly what you need, part numbers and all. They aren't going to look up stuff for you.
And I don't think they will have the RV500.
http://www.airforums.com/forums/show...80&postcount=2