I don't think I'm just lucky, but I have two excellent tubular wheelsets that I bought used for $120, 150 each. Apparently the road and TT and Tri guys are not interested in putting up with the hassle of sewups unless they're carbon fiber and insanely expensive, so classic built up style wheels go for shocking cheap money. I've got one pair with D/A hubs, WS spokes and Reflex rims and another with Chorus, Sapim and Seoul 88s. So this is all top shelf stuff. Oh, and one set came with still good road sewups I use for training and the other with wheel bags. So I'd say used was a very good option.
Oh, I'm running Campy 9s so there's no problem using either shimano or Campy cassettes, just a half turn on the rear der when I change between them.
Ron