I think I would have to consider a couple of things as far as the budget goes, because you won't be living in a full-amenities trailer: 1. Personal Hygiene. Showering anywhere but something rigged up outside your vehicle will cost money. I suppose this is an optional expense, but not being able to get totally clean at least once a month would make me nuts. 2. Laundry. 3. Propane. When on the road, I use propane for a small heater, cooking my food, and heating water for showers. It's not expensive but these things add up.
I would also ask if you've ever done anything like this before. Do you consider yourself a camper? My experience with road life, even in a small class A, is that ... sometimes I just wanted to *really* be inside, with space to move around, a real bathroom, reliable temperatures, no rain beating on the roof, a sense of being in a "normal" space with privacy ... YMMV, totally, but camping in my Matrix was even more challenging because I couldn't stand up in the vehicle and I really had nowhere to be but inside it holed up if the weather was bad. This is a financial question, I think; I dealt with my claustrophobia with a day in a cheap motel every couple of weeks, but I don't think your budget would cover that.