Buying at Foreclosure Auctions?

This first Tuesday of November, my husband and I will be buying an investment property (home) at a trustee sale/forclosure auction, held at the steps of the county court house.....I have chosen 5 possible properties and out of those five, I will buy one.....I have seen all five properties and done all the due diligence on each property....That is, what is owed, what they paid, when they bought it, tax value, year built, sq foot, price per sq. ft, the first lien holder, etc etc....I just submitted these five properties to a title company so they can do abstracts and tell me if they have any other state or federal liens attached to them.....I crunched all the numbers and hopefully stand to make a healthy profit....Most of the properties are in fairly good condition and newly built (1999-2004).....My question is, what more should I look for? Did I miss anything? I realize I don't have assess to the properties, and I have consider major repairs into the cost of all these properties...