Short Sale Discount Due to Non-Paying Tenants

[Justin Braithwaite]

I am currently looking at a 4 family short sale opportunity in the Bronx, NY. The zillow value is 450K and it is bank approved for 395K. I want to justify a lower offer price to the bank. There are currently 2 non-paying tenants that are being evicted. What is the rule of thumb for a discount due to each eviction in process?

Thanks a lot