Regarding your 1999 Holiday Rambler - here's another with very low mileage of 36,284 miles for $25,900. You might compare the two.
http://www.pplmotorhomes.com/diesel/diesel-motorhomes.phpLow mileage doesn't necessarily mean it's bad because of not being driven enough. Have someone check it out thoroughly and naturally, you'd want to see it in person. PPL does basic checks of the normal components such as stove, refrig, etc. but you'd need someone to check the engine, etc. This unit looks extremely clean in and out. It might have been a snowbirders unit which stayed in a southern park during the winters and just moved back and forth.