Craigslist & RV Trader are my normal go to’s. You will get the most bang for your buck by purchasing an older “FACTORY” camper. Avoid owner built or modified rigs like the plague. Then use them as they were intended. If they didn’t come from the factory with solar, DON’T ADD IT!!!. If you need extra power, add a cheap portable generator.
I found many choices available in your area on Craigslist, starting as low as $1500. I searched for “camp* van”. The asterisk is a wildcard, so it will match on camp, camper, camping, etc. The $1500 one was a 1988 Chevy Pleasureway with a pop-up top, one owner, and low miles. It was posted last night, and gone today, so probably sold just that quick. The truly good deals don’t last long and you need to jump on them asap. Also expand your search area to include all nearby towns.
Sitting in someone’s yard, covered with dust, with a faded for sale sign on it is another good place to find dirty diamonds. I have found many fabulous rigs for myself and friends by just driving around neighborhoods and keeping an eye out. Even without a for sale sign, if they look slightly neglected they can often be bought really cheap. I can usally find a dirty diamond that needs nothing more than a bath, within a day or two just by scouting the area, and it is really rare for me to spend more than $2500 for an excellent one.
I like cheap rigs. I could replace/repair any problems, or even replace everything, including my van for under $2500. Split the rest of your budget between an emergency fund and an adventure fund and go have a blast.
"If you prepare for the worst, every thing else is easier." ~ Off Grid