Hello the cost of the installation out the door came in at $4700.00 dollars that includes the studs for the TOGO dome, the uni-strut and studs, the new venturi vent caps and painting the edges plus tax. Expensive depends on how you look at it, I have always been proactive and ensured my equipment was maintained to the best of my ability. I didn't want to one day see delamination in the walls or water stains in the ceiling. If you take a close look and see how your fiberglass roof is actually attached to the coach you might rethink the idea. The aluminum strip that runs down the sides (along the roof} that actually has the screws that help shape the roof over the sides and attach the roof to the sides are just steel screws that are covered by a 1 inch piece of vinyl plastic. What happens over time is the plastic deteriorates and fails or water just finds it way behind the vinyl plastic strip and wicks its way into the structure around the screws. The screws rust and then fail, as one fails it starts to progress to the next screw and so on until you have a sizable leak, by then its probably already created damage. I know that PC's are not know for roof leaks, and in my opinion there are only to roofs to consider, aluminum or fiberglass. You mentioned that your roof has been exposed to the weather for sometime, I ask the question have you pulled the vinyl plastic strip back and checked the condition of the screws? if you take one out and see rust on the threads you have a problem. With FlexArmor they seal all of that so leakage cannot happen. As for adherence issues of the product you might be referring to an application error with poor prep work. You need to do your home work before picking who installs your FlexArmor,Elite RV in Palmetto Fl. is owned by 2 A&P mechanics, who have the best attention to detail you will find Planes don't get do overs). Also if you have an issue with the coating give them a call they will fix it free of charge.. While I was at the facility I saw everything from million plus coaches to inexpensive camper trailers, and a line out the door to get their roofs coated. So you may not consider it as a necessity but there are a lot of people that have did their research and also decided to be proactive and eliminate any chance of leaks from the roof, just saying..