advice needed on short sale!!

2 bd 2.5 bath condo listed for 92k

offered 95k

BOA counter back at 115 now;

they have appraised it at around 124k according to my dual agent. what should I do? I am thinking short sale is supposed to be cheaper otherwise why bother wait for so long right? My agent suggested final price could be between 105 to 110k. My bottom line is 105 but I haven't told my agent yet. Should I offer at 105 which would be my best offer or do I start with 100? I still want this deal but don't want to over pay. Normally what kind of discount can we get on short sales? Another thing there is another back up offer right now so the bank has asked the back up buyer to make another offer too. All of you experienced landlords here please advise.