Ksg5000 makes a great point about price point RVs. IMO, there's zero need to buy new or nearly new and spend a great deal of your money. Whichever route you go on RV type, you can find one in great asthetic and mechanical condition for only a small % the cost of new. Plus you're a plumber. Bout the only real things to go wrong with a RV besides the fridge is plumbing/hvac related.
Your interest in TTs should be run to ground. IMO, plumber = need a truck or Van. Not necessarily if you're working for someone, but side jobs = CASH! Hard to haul sticks of pipe in a Prius!
If you think you'll be more transient, then a Moho might be a better choice, but if you're making the RV home base in the same location/area for a while, you get more bang for your buck out of a TT and again, IMO, a tradesman needs a truck.
Again, good luck!