Possible to install W/D? Full timers. First RV.

To answer your question about age of unit. You can find an older well maintained unit. Our first RV was 20 years old. Our current RV is 10 years old. In great shape. You need to examine them carefully, looking for leaks and delamination and tire age and condition, as well as condition of the interior and the roof.

You could expand your search to 3-10 years old. If you are going to move the unit twice in five years, you could hire a company to move it for you instead of buying the truck.