http://www.unclesamsretailoutlet.com/Catoma-Wolverine-Coyote-EBNS-p/15249-0172.htm
There are some older, very similar, military shelters made by Catoma, available w/o the "pop-up" feature, and for less money.
I've tried the older, non-pop-up shelters, and set up right, they work. I think the "pop-up" feature is a dumbing-down of the original tent, but requires such specific deployment and more importantly stowage procedures as to be problematic.
FWIW, I bought a couple of very expensive Mountain Hardware tents on this Site in a Group buy that looks almost identical to the non-popup, GI Catoma tent.
The essential problem with buying used tents is that the polyurethane (water-proofing) coating on the inside of the rain fly and bottom of the tents/shelters is quite susceptible to deterioration over time, and more importantly, to heat.
There are ways to "over-coat" the OEM polyurethane coatings with newer stuff that will accomplish the same waterproofing purpose. This can be done at considerable amount of labor and expense. Not worth it unless the old tent is basically a gift, or an [I]extraordinarily[I/] well-made tent.