My lfs sells them as they sell BGK's (which look in poor condition and are losing their black colour, going white in places!!).
The pipes are real expensive though, especially as it's just a short piece of pipe. I had one, it looked bad in the tank so i removed it. Also he didnt use the pipe much, he's quite active and not all that shy.
i thought you could find clear pvc??? maybe it was something else i saw then. but anyways i jsut used plants and a rock cave like thing. they just liek to feel safe and hidden. but i did buy a hampster tube for it as the one i picked out looked more "natural" (if that's possible) and the nit died, so then i went out and bought a hampster... i know horrible huh? but i wanted to use it