Going on the older end of the scale, cruising craigslist and the local dealers. Trying to keep it around $5000, but everytime I find a decent rig, it is gone before I can get out there. Just venting...
I'm not sure that leaks are more common in the Northwest. My guess is the opposite. We generally don't have the extremes like other areas, and it doesn't usually rain as hard as other areas.
However, I agree you should inspect a used rv to look for leaks, but also to make sure that the basics work.
If I was looking in that price range I'd also add Northern Lite to the list.