The worst that the seller can do is say no. Right now they pretty much have to deal with you since you are still in contract. If the house is not appraising at your offer price, others may have the same problem. Listing agents often bluff about back up offers since they don't want you to ask for anything but they often done have anyone formally in back up (esp on REOs). Doesn't matter, they are working with you now and you have a right to ask. They might just want to get the sale over with and they might decide to just reduce the price.
I recently asked a seller to reduce the price for my client and they did it. They reduced the seller credit to buyer a bit but they did it. Long story short, the buyer still gets the home she wants and everyone is happy.
One other option that you might consider offering if they don't go for the price reduction is to offer to increase your down payment by $15,000 (if you have it). Or you can split it with the seller - you come up with $7500 if they reduce the price by $7,500. - Wed Jun 10 2009, 19:10