advise on making a short sale offer

[Dave Stevens]

Hi guys, newbie here working on my first short sale. I just got a payoff figure form the lawyers, here is the break down:

Principal Balance: $ 325,243.93
Interest: $ 12,499.86
Late Charges: $ 616.96
Escrow: $ 6,397.95
Property Inspections: $ 172.20
FHA/PMI: $ 581.19
Servicing Fee: $ 125.31
County Costs: $ 280.25
Sheriff Costs: $ 7,599.39
Additional Costs: $ 485.00
Attorney Fee: $ 1,325.00

Recent comps show similar houses selling for $245K to $250K with approx 150 days on market. I want to make an low offer the shows I'm serious but not too low that shows I don't know what I'm doing. Any suggestion?