How often can you not find a buyer in time?

[Jason Munger]

I understand the process...thinking of getting into it as another "vehicle" for investing.  I'm curious though, how often are you not able to find a buyer in time?  What then?  Just buy the house and sell it conventionally?  In that case, do you only go after properties you could theoretically purchase?

Backing out of the deal would be unethical, right?