I think I have seen this person list a Fastlane at least twice now. Both times the card "sold", and each time it is listed again the starting bid and buy-it-now prices are higher. Either this person has alot of Fastlanes, or something fishy might be happening.
To upgrade it to the 256MB version required swapping some chips on the board (Pal or gal, not sure) and replacing the eprom with a newer revision.
Realistic prices have been more around US$100-$120, though some might think that overpriced as well. Considering the other ram upgrade paths, it's not bad. The 30pin 4MB simms can usually be picked up real cheap on Ebay in lots. So for maybe US$130 or less you pick up an additional 64MB fast ram and in a 4000D, a good SCSI controller.
-David