When writing an offer on a short sale, one of the first things we ask the listing agent is if the short sale has already been approved by the bank...the waiting time is horrendous. Even when a short sale is approved and there is an offer on the table, it may still take 30 days to get an answer from the Lender who has the final say in whether to approve, reject or counteroffer an offer.
In the meantime, the longer the short sale takes to sell, the closer it gets to being a foreclosure. We've watched some short sales with no activity. Then as soon as it was foreclosed, that's when we made the offer. The response time from the lender was a heck of a lot shorter than a foreclosure.
PROS: If you are successful, you may but the property at a lower price than market. There is room for negotiation (don't expect a lot!)
CONS: Long process. If you don't keep looking at what else is available, you may miss out on a good deal while waiting for a short sale to be approved. Some short sales are still listed at market price, and lenders may be unwilling to negotiate a much lower offer Even if a seller accepts your offer, the final decision rests with the Lender. If other offers better than yours comes in, the Lender may choose the better offer --- and you've just wasted time waiting for a rejection.
Take a look at this link about Buying Foreclosures and Short Sales.