Good luck finding any bus under $2000 ... in functional condition. There might be an odd one or two, but most buses that cheap are likely to need a lot of work to get going again. Oddly enough, the minibuses and full size ones ... in similar conditions ... seem to auction for about the same money.
That said, I snagged mine for $3500, with owner financing (my company does a lot of business with his and we've been dealing with each other for 7 years, so he knows me). It's not without minor problems, but it runs and drives and stops, so all the major systems are in working order. Mostly I've been fixing the lights, parking brake, fuel return lines, removing lettering, and the exhaust will need some work.