You may want to try and repost this question in Northfield, IL - it ended up in the Northfield, MN newsgroup. I would probabaly recomend that you wait until after the redemption period to buy this home. Chances are likely that the bank will sell it for a loss when they try to resell it.
It is too far into the process for you to just buy it. The auction may be open to the public, but most likely a representative from the mortgage company will be there to buy it. If you go, make sure you do a title search before you bid.