Well, you're right, your budget isn't going to give you a large number of options,
but I ran a basic search on rvtraderonline, and came up with a few hits in the
van conversion grouping, gas or diesel, $0-$10,000, any manufacturer, new or
used, and any distance from your zip code.
http://www.rvtraderonline.com/find/sear ... YearESC/
Some of them don't look too bad, but you'll have to follow up, if you choose to.
You'll have to send some emails, or make some calls, or do a bit of driving.
Basically, you'll have to take it from here, but there are tools avauilable to make the search easier.
Maybe you needed to refine your search a bit?
Hope this helps.
Good luck, it's not always easy.