Old motorhome have walls that fall apart thanks to the windows leaking between the frame and wall. With any RV, you need to go around and tighten the window frame screws once a year. After about 10 years the butyl tape used a sealer must be replaced as it will be dried out and fully compressed allowing the frame to contact the wall directly and it will leak. Sealer smeared around the perimeter of the window frame is useless. It will leak again very quickly. Do it right. As for the RV, $1700 is probably way too much for something that may turn out to be junk.
Clicky