I bought a set of Gigantex tubular 50mm deep road rims a while back with plans to build myself a wheelset, but never did, and decided I wasn't likely to. So, this set of rims is completely new and unused. Not Chinese, but Taiwanese, sourced from
http://bikehubstore.com/ and were something like $220 each when I got them. (not affiliated with BHS, but I have bought a bunch of stuff from there and have been really happy with them)
https://plus.google.com/photos/118048517346415993560/albums/6077658058463149761?banner=pwaAt this point, just looking to get rid of them to help fund my Chiner project, so thinking $100 for the set + shipping. If you supplied the hubs and spokes, I could do the build for you as well, I've been building wheels for myself and others since the early 90s.
As you can see in the photos, it's a 3K weave under the tire and at the spoke bed, but a UD weave on the sidewalls.
I should also note that these are narrow, not the new trend towards wider rims such as 25mm. I think they measure about 21mm at the brake track.