I thought car parts was overpriced

This is a charity auction.
It's being backed by Apple, for a charity that they have an interest in.
The what isn't relevant, and whom ever buys the computer will write the cost off as an tax deduction. At this level, with Apple involved, putting the auction on eBay is more a show of "look where were and are now."
More of a novelty that the same bidders that this is targeted to, get a chance to put us common people in our place.