I have one of the 10x10 swim throughs left I was trying to sell and I would ship it but you pay shipping. have some used ones too for a little less but same deal on shipping.
Ted Cantrell has some 12x12 swim throughs.
From me or ted you are looking at half the price of a Comstock and IMO just as good a trap.
Also have a few 10x18 used swim throughs.
Probably should talk prices by PM if you are interested.
Maybe depending on where you are at we could meet sometime and save shipping.