Only the banks know the answer to that question and each bank is a little different in their approach on how they market their properties. Some banks sell them in bulk, some will fix them up in hopes of getting more money for the property. The banks are releasing them slowly to stabilze the market and it seems to be working because inventory has tightened and values are increasing.
We all hear rumors of how much inventory they have and are holding back, but no one knows the exact extent of how much inventory they are holding. I personally heard some substantial numbers and often wonder where are all of these homes?
When a nice foreclosure hits the market, there usually are multiple offers with many offers going over asking price. One example for me is a foreclosure that was listed at $60,000.00 and we bid $79,000.00 (CASH) and we still lost the offer. So low inventory drives prices up.