I had wanted a 10 gauge due to it being the biggest of the common shotgun gauges. After some searching, I ended up with a Stevens single shot with a full choked 36 inch barrel. I believe I paid $220, might of been $250. It has a 3 1/2 inch chamber. Good gun and probably the cheapest way of getting a 10 gauge. NEF also makes a 10 gauge. Used can be had for $200-$250.
Now if I can just find an 8 gauge on the cheap.