Triplex appraisal value

[Jeremy England]

I'm thinking of bidding on a triplex at a county auction and wanted to get the input from people here on placing a value on the property.  

The building is in a c-d neighborhood, although the street it is on is better than the other blocks due to less traffic.  The market rental rate for the units (after repair) is 625/mo, this coming from another building across the street with equal sized, clean, painted, with newer cabinets   

The tax assessed value is 72000.

Unsure of repairs needed yet but if I guestimate 12/sf i'm looking at about 25000 (I'll verify this before bidding)

Comparable sales do not reflect much due to the number of sfh surrounding the property.  

If I price it according the cap rate method, I come up with 122000 

Bank's highest bid is 70000

I intend to BRRR this property, but not certain if I'm looking at a deal.

72000 purchase price (foreclosures in this area that sell to 3rd parties typically go for approxmately assessed value)

Repairs 25000

Buying cost: 500

evictions/cash for keys: 1500

Initial cash outlays: 99000

Annual revenue: 22500

Taxes: 1417

Insurance:  1500?

Vacancy: 1800

Maintenance: 1200

Cap/ex: 675

Management: 2025

Lawn maint: 480

Water/sewer: 1200

NOI: 12233/.10 = 122330

ROI: 12.3%

question is what method would the appraiser use to value the property.  

anything it look like I'm missing here?