About 5 years ago... at a RV fix it place that is not a dealer and takes appointment to get in. 110 a running foot and 100 a hole (vent or any hole they have to make, skylights, a/c, even vents on tank, (only 2 inch hole) etc) Does not include any replacing of wood, that would be at shop hourly rate time and materials. Or any new vents, covers etc. That is what worried me. What if they stripped off old roof and there was lots of damage to wood. Price would be sky high to pay someone to rip off old wood and replace. Wife being a retired building manager called and talked with her old roofing contractor, EPDM and rubber roofs also used on regular buildings also for many years. He recommended checking out
https://inlandcoatings.com/product/rc-2016/I called inland coatings and they had sales rep contact me. Turns out he also has an RV and gave me lots of hints for applying and how to's. I ended up paying $48.00 per gallon at roofing supply house (instead of $110.00 at RV dealer for other roof coating stuff) Total I spent less than $200.00 about 5 years ago and couldn't be happier. I don't cover my rv in winter and I get lots of rain. Read their case history's. In my area they did big project
https://inlandcoatings.com/case_studies/a-sound-solution/ But not sure about your area with lots of sun. At the time I figured the worst is I would be out $200.00 if it didn't work.
Use brush, not roller, apply second coat, then another coat following year. Can't over emphasize prep work, so you start with clean sub surface and removing a/c is a learning experaince first time. Takes long time to dry (days) because brush is applied thicker, but gets into tiny cracks better.
This was done on our small class C "Majestic" (old ex-rental). Next summer going to do our 30 Arctic Fox trailer. Our Majestic actually has thicker EPDM than our Arctic Fox. My Arctic Fox dealer does take off from trade in value because of a coated roof. But in his used rv side, lots of trade in's with out new roofs. So just a bargaining chip IMO.
Anyways...Just my opinion after doing my own 5 years ago. I'm very happy with end result. Neighbor did it also but used stuff he got from big box store and only used a roller. Didn't turn out as well IMO.