Rule of thumb we've used is to find out if the gun is currently being made and never offer more than a new one could be purchased wholesale, condition being the deciding factor, generally a hundred or so below that figure, and some guns are slow movers so it'll be even less...every Shop is different. Dealer wholesale on a 164300 Model 686 + L-Frame 357 Mag/38 Special +P 7 Shot 3" (least expensive 686) is $846. and there's shipping/insurance/lots of paperwork that go along with it...Five hundred seems light, but if it's something I have to invest my capital into with no guarantee of return or time involved, then that's all I might be willing to put into it. YMMV