I have a old suzuki King Quad, rear independant suspension, 4x4, manual gears. Paid maybe $1300 for it. They hold up really well and you can work them hard. Trailer is a wrecked pontoon trailer that the back end was cut off of and axles moved forward. 3500# capacity axle. Its only about 4x6 now. I dont have sides on it, just stack em up and strap em down. The set up gets a lot of wood moved. Paid $600 for that.
I also have a a Isuzu rodeo. 6 cylinder motor, 4wd, heat, radio, locks in case I want to leave the saw in there. Paid $500 for it, and I can move a LOT more wood with that beast than the quad. Its not that much bigger in the woods. I originally wanted a tracker for size, but it worked out fine. If you want to go cheap, theres a lot better options out there than a quad. MAybe not as much fun though....