The people we paid $35,000 were quite well off in that in that town. Hell, I rented one of the largest houses in the area when I moved, and only paid $800/mo (for 4,000 sqft). Nice two bedrooms ran $400-450, with three bedrooms running a hundred or so more.
The single wide culture fell into three main camps, as far as I could see:
1) Those who bought land and put a single wide on it, so they could own their place. Usually the intention was to some day build a house. Not a horrible decision.
2) Those who were renting, and opted to have a smaller trailer on a lot of property (to be able to have horses, etc), instead of going for a real house in town. I can respect that decision too.
3) Those trapped in the "pay weekly" rent treadmill. I feel bad for this group, because they're paying as much or more overall for their trailer rent as a decent rental house ran. But it's almost as bad as the payday loan treadmill .. once you get on, it's hard to get off.