If you are looking for classic games, stick to Craigslist, and the collector community.
These auctions are nothing like the old Superauctions when there were hundreds of classic games and parts sold off and big rows of pinball machines and parts. It's hard to even comprehend those kinds of auctions nowadays. You will never see them again in So Cal, there just aren't that many machines sitting around anymore which can be disposed of at auction for auction type prices.
These auctions are mostly geared towards games that can still be operated for money...because that is what sells for decent money nowadays. If you look through the stuff they are selling a majority of it is shooting games, driving games, neo geo and other kinds of Jamma games. Yes there are some older games but there is just a token amount.
Their idea of a rare game is Captain Commando...
Plus a lot of the stuff does not go that cheaply, unlike the old days where stuff sold at the auctions for auction prices. The prices at these auctions are quasi-retail.
Kind of fun to go and look though, and BS with other collectors. Sometimes you might find a deal but like I said it is nothing like it was in the glory days.