Just to add some ways to save a buck here and there:
Passport America offers a directory to campgrounds that offer 50% off to members with certain conditions (not when they can sell out for full price). They are usually a bit out of the way and either new, just getting started, or old and a bit rundown.
Escapees which is a club for all RVers, but is especially good for Full and Most Timers. They provide an answer to how to handle mail, and many campgrounds at reasonable prices. Check them out at escapees.com. To my way of thinking they are not a luxury like FMCA.
If you are on SS Disability, I believe someone mentioned the
Access Pass which provides free access to many federal parks and half off at most accommodations in those parks.
I will not join in the chorus that says this may not be the best idea. It can be made to work if you are willing to make the adjustments to make it work. It probably will not save you any money relative to renting an apartment and the argument against renting - you pay and get no equity - also applies to your coach, you pay and end up with no equity.
Just for an idea of values. WE bought new an '04 Southwind 36E for $125K (give or take) we lived in it most time for 8 years and drove it 110,000 miles. When it was time to trade, most dealers considered it worthless because of the miles. I can't say the engine wasn't going to breakdown in the next 10,000 miles, but it was the Chevy 8.1L and it had been very carefully maintained and had never missed a routine service interval. I figured it had another 50,000 miles before needing a major overhaul. A coach like that would be worth 10,000 to 15,000 today. So don't avoid high mileage, to get there you have to use it and maintain it which is better than leaving it sit in the yard or campsite year after year with very little use.