If you have an accepted purchase agreement with the seller and are waiting for a response from the bank, they usually (unless your offer is way off the mark) counter if your offer is too low.
...your credit will not have an effect of the short sale lender's decision.
You could have waited and the current listing agreement would expire and you can wait for a new real estate agent to list the home and purchase through them. Will it be a better price? No one knows.
Or you could wait and the offer that may have been submitted this morning will be accepted because it is the only one on the table. Will it be a better price? If your offer is higher or provides better terms, than the existing one...it could be a fantastic price! But, no one knows.
With out more details everything is speculation and unless a responder to the question is the actual listing agent, the real facts can never be known.
As you know, short sales are the wild, wild west of real estate. The rules are fluid, the results inconsistent, the process lacks transparency. The emotional roller-coaster ride known as short sales is not well suited for those who see conspiracy behind every action. You need to trust those working on your behalf, otherwise you most certainly will be counted among the 70% of short sales that never close predominately due to the buyer losing faith, getting happy feet and quitting before the process has matured.
Consult with your real estate professional and have them review the short sale process in detail with you. If this is still an option you want to pursue, sign the buyer agreement and go find a great home!
It appears that additional information may help you gain more accurate information. But as stated earlier, unless this is a "bank approved price" the actual sale price generally has very little to do with the asking price and is negotiated with the lender after the seller agrees to a price they will accept.
The list price is a guestimate by the listing agent and has nothing to do with what the lender will accept as an offer.