To use to go fishing from time to time 50 miles from home old chassises càn be OK. For cross country trips radiators may need recoried or replaced, tires, belts. Roof condition is #1 on house concerns.
In 2007 we bought a 1993 on a 1992 Chevy chassis with 91K miles for $7995 from a motivated seller with great tires and a remanufactured transmission. In 2011 it was flawless on 8000 trip to the Pacific through 17 states in 31 days in part due to our working on it for 4 years. I used it to teach home and auto repair to the twins.They asked for a MH and got one at age 9 but came to regret it. :-)
The 31 day trip was awesome and they turned 14 when we were in CA. Now they are seniors in high school. The daughter is working part-time doing well on the job and the son just this month passed his Eagle Scout board of review. The old MH gave them a lot of work and travel experiences. We made many shorter trips like swimming meets, parks, museums, etc as test run's and building my driving skills.
My take away. Do not buy anything over 10 years old unless you are looking for an expensive and long project.