Off-white can be tricky to maintain, and it makes sense that it requires more work to keep it looking good. The price of $1,100 sounds steep, but if it includes compounding, polishing, and regular maintenance, it could be worth it to protect your investment.
I am faced with the same problem.
6 years in the NW, uncovered, having it washed and waxed every 6 months, and the finish was like new.
3 winters in the SoCal sun, uncovered, having it washed and waxed every 6 months, and the finish is seriously oxidized (and graphics are starting to crack.).
I tried a variety of oxidation removal "kits" (on a small test area) and the results were hit or miss. Not safisfactory by any means. Then I tried Turtle Wax "Premium Rubbing Compound". It does a good job; however, doing it by hand takes me an hour to do about 6 square feet. (I'm no good with a buffer.) Since this is way more work than I want to put forth, I'm going to have it done by a mobile detailer, and I expect to pay at least $1100. (The guy I may hire is going to do a sample area, and then I can decide if it's worth the cost. (As I get older, 77 now, I'm more willing to open my wallet and pay someone else to do the work!) If it turns out good, I may start covering it over the winter since I expect the SoCal sun will oxidize it again in short order.
We have a 2012 Carriage Cameo. We try to wash it every 6 months, min. First I do the roof with Dawn and Murphy Wood Cleaner, the on the sides I use Meguiar's Ultimate Wash and Wax. Then after that I go around the RV and spray all the seals with silicone lubricant(inside and outside seals). Then I check the integrety of the sealer to be sure there are no potential leaks. If you have "chalking" I don't know if you are beyond help, but you can check on line or at a automotive store to see if there is a product that helps with the chalking and also cleans and waxes.
Good Luck
