Understand that it will make absolutely no differnece to you what your house can sell for, or will sell for:
The bad news is that you won't see a penny of that money on a Shortsale,
The good news is that you won't be charged for a penny of the difference.
I trust that you truly have a HARDSHIP that you can sell your Bank on?
Have you composed your Hardship letter?
Have you communicated such with your Lender?