There are two types of foreclosures, those that are going to auction and those who are through the auction and now listed with an agent. Auctions are cash only events. You can't preview the home, have any contingencies or inspections and all sales are "as is, where is and final". You shouldn't consider these. Some can be a fair value, others are a flat out rip off.
Buying a home is too big of an investment to narrow your focus too much. Bank owned homes, conventional sales and short sales are all listed with licensed agents and can be shown by an agent who represents your interests first. Consider everything, not just bank owned. There are some good buys out there from motivated sellers. You should buy a home you love, it will be a better investment in the long range than one you got a deal on, but don't like the style, location or other issue.
Find a great local agent and a great local lender. Get pre-approved and start shopping the entire market. Best of luck.