I've been watching, and they've dried up a bit in the last year. There's one in Las Vegas right now that looks O.K., on Craigslist. Gillig, mid-engine (based on year should be desirable 855 big cam) and 5 speed. $2500 Best deal right now. Probably won't find much east of the rockies. Be careful, a lot were in service in the NW, and then moved elsewhere. In a Gillig, look closely for corrosion where the window posts meet the roof. Also check wheel wells good. Mid engine Cummins (esp the 855) are probably the most powerful skoolies ever, made by both Gillig and Crown. BUT there's very little room underneath for tanks, propane, batteries etc., Rear engine Gillig w/ a Cat 3208 and full basement bays (like mine!!!!) is hard to beat. They all came with an MT643, spicer 5 speed or Fuller roadranger 10 speed. Big cams might have had a bigger auto....
The Gillig on Everett WA Craigslist has been for sale for ever, at least 2 years now......hmmmm maybe not so good? Pat Young in Fresno just listed one, but sounds like it may not quite be ready. Don't know how good his guarantee is. A few Crowns around, but they tend to cost a bit more, and most are mid engine (I prefer the rear engine). There's quite a few both Crown and Gillig busses still in service in Fresno; I don't know if/when they will hit the auctions. Most are in private hands now.