Wish that site was for real, at those prices I'd buy a couple of 040 & 030 boards for some of my old miggies... 
(It's a lot cheaper than Ebay...)
SoftHut did have some of them in stock as of a few weeks ago and they are a little cheaper than listed on the link above.
GVP Typhoon A1200 030 40MHz Accelerator $169.00
A4060DT - 060 50MHz with SCSI II Interface $445.00
TekMagic A2000 060/50MHz Combo $479.95
They are new-ish (refurbs I think) but the prices are pretty good considering.