If your not interested in shooting doubles for awhile might I suggest you look into buying a new BT-99. You just can't go wrong with one of these, even if you buy a used one. Good Luck and Break-em all. Jeff
Check out Gunbroker.com, Auctionarms.com, and see what bts are going for. The local Gander Mtn has them for around $1100, our local trap and skeet store lists new ones (w/o ejector) at around 1200. Used...just got a two barrel model, 32" mod, 34" full for 709 plus tax. I'd think a well used one that is still tight could be got for 600-800 (sold a first model for 650 a couple yearfs ago). Can't go wrong on a BT if it is new or well cared for.
I really would look for one with invector tubes rather than non-tubed