I got one from eBay for only $86, and it works great. I'm sure the reason I managed to get mine so cheaply was the seller described it as an RPM controller, so anyone doing a search for an AIC wouldn't have had it included in the search results. There was only one other bidder on it.
BTW, the one you provided a link to is a member over at TDS, and is a great guy. He seems to have a big supply of them, since he has one listed quite frequently.