Look around at campgrounds in the area you are thinking of. Many campgrounds will have "seasonal" campers for sale that includes a lease agreement for long term staying at the campsite. These campers are already setup and ready to move into.
I second looking at a TT, or Travel Trailer. For your money, you could pick up a very nice TT, likely with more living area than a Class C. When you find a campground you like, the management there probably will know someone who can tow the camper to the campground, or the campground itself may run some sort of towing service.
Double and triple check with the campground management about monthly fees, electric rates, maintenance fees, etc. Also, some campgrounds may refuse you if you outright say you will be living there full time. Actually, local zoning laws may require them to not let you stay "full time". If you stay as a "seasonal", you may have to move out of the campground for a certain amount of time, sometimes just a couple weeks.
Good luck!