Good starting offer for a fixer upper short sale?

[David C.]

I am looking at a short sale with list price of 59900 with tax appraisal of 72k/eppraisal of 68k. Realtor sent 30 day comps for the past 6 months of 35 to 37k. Needs about 10k in repairs. I was wondering if 23k is a good starting offer. I was looking to immediately fllip after the 90 day period. What is a good formula to use when trying to find a good price for a short sale?