Do your homework here and ask questions...if you have 5-6 grand for an 8 ft. CO you can afford either a 100% rebuilt 70's era (yacht looking interior) or one that is a few years old. You will want to avoid those with particle board interiors that swell up and fall apart when they are exposed to moisture. You have to either be OLDER than those or NEWER than those.
Don't even THINK about that one up in Reno on the red pickup....I inquired a year ago when it was down San Diego way and got the brush-off when I asked legitimate questions....such as why the photos were of TWO DIFFERENT CAMPER INTERIORS!
Try to keep a few bucks set aside to replace the Pirelli seals, maybe the butyl seals under the window/door eyebrows and around the window frames...and add some sealants to them after they are installed.
Start by reading about every single post in the ALASKAN section and pick up a few hints here and there...and what to watch for when you go to look at a possible candidate.