I spent quite a few months looking for a small dump truck also. Brand wasn't important to me, just price and something in decent shape. I decided I wanted gas over diesel due to the gas trucks being much, much cheaper. I also wanted hydraulic brakes. I'm not gonna tow anything, and getting the air brake endorsement is something I wanted to avoid on a non-CDL truck.
I ended up buying an 83 F-650 for $3,250. GVW is just under 24,000 lbs. No complaints, it's a nice truck that will haul 6 yards of dirt with 10 inch sideboards around my land. Napa has all the parts I've needed for it, which they have in stock.
I looked in the truckpaper, traderonline and ebay for anything that would meet my requirements, but not be so far away it would cost thousands of dollars to get it here. I also did just what your doing on this webstite, I asked around. Just about everyone I came into contact with, I asked if they new of a dump truck for sale. I got some good leads, but just not what I wanted.
Ebay was probably the most bizarre for trying to get a fix on prices and finding something fairly close. People would get into a bidding war five days before the auction was to end driving the price way up. Then the last second bidders would also come in with crazy bids. If you watch the site for awhile, you'll also notice that some of those trucks come right back on again with the crazy bidders not paying for the truck.
Of course, buying a truck unseen is crazy from the beginning, but I found it helpful in feeling out the market.
American Classified, or the free local classifieds ads are a really good source for fair priced items found locally. I called on quite a few in my area, only to be too late.
There really is a huge demand for small dump trucks right now.
In the end, I was coming home from looking at a dump truck in the Dallas area and decided to take the scenic route. About half an hour from my place I spotted my truck sitting on the side of the road with a for sale sign.