I would guess that the property was taken back by a lender, and they hired REDC to do the auction. REO properties have to provide certain disclosures, and depending on how the contract was written, you should have several days to review the HOA documents and if they don't meet your approval, you should be able to cancel and get your deposit back. If they refuse to return your deposit, you may have to get a lawyer, but try negotiating with them first.
With many condo associations, the dues have been delinquent for a period of time prior to the foreclosure. If there have been a lot of foreclosures, the HOA will have to increase the dues to make up for the lost money that they didn't get. I think the maximum increase is 20% without having to have an election, but that can be a lot of money!
See the legal discussion about this at the California Association of Realtors website (referenced below.)