[john] Cetainly is a hard question to answer. In our last year of RVing we stayed at campgrounds that cost from $60 to $300 per month, some that were $10 per day, some that were $50+(FortWilderness) per day. And I'm sure some of these a lot of people would not be pleased with. And it depends on how much you move around because;(1) fuel is not cheap, (2)weekly/monthly rates are a lot cheaper than one night stands ((??)). I can't separate gifts to grandchildren from dining out and truck service but can say we spent pretty close to $30000 excluding payments for truck/fifth wheel. That help? Probably not. But one thing to note, I've heard more than one say "this sure isn't a way to save money".
[Art] The cost of fulltiming will be different for each person. It depends on your spending habits that you have developed over a lifetime. Some people eat out a lot, others don't. Some like movies and theater, others don't. Some spend a lot on tobacco or alcohol, you get the idea.