Man this is so confusing to me.
In the first post you list all the rents and it comes out from what I could figure to be $44,000 a month. Maybe I'm off a thousand. However, that is a big difference $62,500 vs $44,000 a month or $18,500 a month. Curious with it just being nine units what the real potential is to make that extra income monthly. Not sure how you debt service this for $240,000 a year when just on the interest at a min of 3% is $170,000 a year. ($170,000/12=$14,166 per month. Then the principal on $5,100,000/360=$14,166 a month= combined $28,332 a month. Not $20,000 a month.
If the true income is $528,000 vs. $750,000 I would definitely be saying no. Even at $750,000 a year in income the above is just to debt service even with 40% down on $8.5 m. Besides debt service you still have taxes which hopefully is figured in to that $140,000 a year. Not to mention your 2% loss on rents. Depending on what the actual NOI is rather $528,000 or $750,000 an associate of mine says offer should be 10x the NOI. So in this case if NOI is truly $528,000 offer should be $5,280,000. Then re evaluate your numbers and see if it makes better sense to make an offer or not.
I'd be saying NO. One of my 1st offers in a long time I'm working on now the numbers are like this.
Appraised Value $1,600,000
Asking price $1,100,000
NOI $525,000
Sweet mixed use property :) Numbers like this can make sense up to like $5 million. Always principal+ interest. Then taxes usually on commercial are figured into the monthly numbers. Residential offers if wholesaling usually most investors want down to 60% of appraised value.
Good Luck :)