Yes, that's the auction that I was referring to.
I doubt that you will actually be getting a Mediator SX. You need to check if it's the 6 PCI slot version, or 4 PCI slot version.
SX is newer (6 slots),
Mediator PCI 1200 is the original version (older, 4 slots). There are also other alternatives such as the lite 2 slot version.
SX is slightly superior due to reworked logic, obviously more PCI slots, direct ATX power supply support, and I believe it can also support m801 audio chipset, and the old one cannot.
Since the seller says "it was one of the first ones, before they brought out the other variants", I highly doubt it's actually the SX model, but probably the original. :-(