Is it a good idea to buy a condo from a builder's auction?

The reason that the builder is selling them, is because it is not his money that needs to be collected. What is happening is that nobody is buying them, and the bank is "calling the note," meaning that they want the money for the loan right now. So, the builder is stuck trying to get the money for the loan before the bank forecloses. There may be a reason why they did not sell in the first place. Be careful here. It may just be a case of a project that was started at the wrong time or there may be another reason why they did not sell.