There's a somewhat spartanly-equipped 030 Cube, 8MB RAM, 660MB disk, with monitor ( 330122485306), and a more comprehensively equipped Cube with 4 extra motherboards. Looks like all 68030, but at least 2 have NBICs installed, which is odd. One (upper right in the pic) might be an 040, I'm not sure. ( Item number: 180120452313)
This last one has monitor, cables, manuals, printer, etc, and two of the spare mobos have some RAM on them. The Cube itself looks like the 030 type, but with a floppy drive jacked on, sitting outside the case. I'd have to look at mine to be sure, but I thought that 030 mobos didn't have floppy controllers. If that's actually an FD and not a SCSI FD (looks like it's using an internal ribbon cable), then it's probably an 040 mobo.
Both auctions are in the USA and have a bit over 6 days left.
There's also a fair few SPARCstation 5 and 20 for sale, for those who would rather run on Sun.