I was thinking the same thing, but they are indeed pricey. I have seen them in person and they fit pretty well. Even better are some of the other after market seat covers... I saw some once and they fit better... I think these were actually sheep skin? VERY comfortable!
Keep us posted, as I am still up in the air about the OEM ones - $300 certainly won't break the bank, but a bit more than I want to spend for something I am not exactly keen about.
-David