Questions on a Short Sale

Ok. So. My hubby and I found a home. Beautiful. Its a short sale. Crap. We made an offer anyway. Full price, according to the listing agent. $249,000. The seller accepts. The bank takes less then a week and counters. $275,000. WTF!? WHY was it listed at $249,000 then?! So WE counter with $260,000. Nope! Bank wants $275,000. ARGH! We were the only offer they had gotten on it. We just cant do $275,000. The payments would kill us.

Can we wait a few weeks, then offer $260,000 again?? Would it be worth it? I THINK the bank is Countrywide. But he (the seller) supposedly has TWO mortgages. One with Countrywide and one with WAMU. He owes $320,000. The loan was a construction loan and was due, paid in FULL on June 1, 2008. I dont know if any of this matters, but I am just throwing out what I know. We have an agent and she has been helpful, but I would like other peoples opinions on the matter as well. Thanks!