What kind of shape is your Cube in? Sounds to me like you got the better end of this deal, well done. I watched a Rev. 0 working Apple II, with 2x disk drives, 2x joysticks sell for ~659 6 weeks ago. The auction ended on a Friday night at 1AM so I believe that's why it was so cheap but yeah regardless your getting a screaming deal. I've been watching NeXT Cubes go for 750-1450 over the past few weeks so that alone is well worth it! Please post some photos of your Cube once you receive it.

Also, do you have a keyboard/mouse, and display? Without those, your just going to be able to look at the Cube.