We did our 35 footer in Allure vinyl planking for $400. Let's say your material will cost $700. I did mine by myself in 2 days. Pros can do it in one. Now figure out what is reasonable to pay 1 or 2 men to work for 8 hours in Fl. I would say $1100 max. $200 @ day is a super wage in FL.
Valances are just plywood covered with material. A nice material is going to be in the area of $30 @ yd. I did our 8 valances in 8 hours using a pair of scissors and a staple gun. Again, do the math. I've never seen any kind of RV shade that wouldn't take more than 15 mins to install with the correct size in hand. I don't know what all else you are thinking about having done, but let me leave you with this thought.
Florida is riddled with mobile RV repair businesses and you will have no problem finding someone to do your work, especially in the more prominent resort areas. When they arrive and see your custom painted HR with matching trailer and show Corvette, the price will at least double. If they told me $10,000, I would laugh and say $5000 tops. If they don't budge, Just tell them I have 5 more bidders coming, then watch what they do