Plan C. Spend $20,000 on an older A and budget $5,000 to get it thoroughly checked out and any issues fixed. Then go happily RVing. One of three possible outcomes:
1) You love the lifestyle, and you love your RV. You have $75,000 to spend on camping fees and such.
2) You love the lifestyle, but you want a different/newer RV. You sell your RV and buy another one.
3) You hate the lifestyle and you realize you've made a mistake. You sell your RV for pretty much what you paid for it, since older units don't depreciate much.
By contrast, if you dump $100,000 in a new or used unit, extricating yourself might be difficult, and if it was a new unit, costly; you'll get hammered for 25 grand just from driving-it-off-the-lot depreciation.
