Purchase price valuation of 8 unit property

[Dan Beddome]

Hi guys, I'm a new investor looking to acquire some knowledge on how to value an 8 unit property I found, the property is on 2 titles with 2 buildings on each title, and each building has 2 units one up one down, 4 buildings and 8 units total, so they are not really classified as commercial so I can't base my numbers on NOI and cap rate.

it's not very easy to find comparable units in the town, because it seems to be the only one like this.

it has great potential and does need a lot of work, but it would cash flow very well, the rents are well below market.

would it be a fair assessment to use last years tax assessment of the properties as a starting point to run my numbers to come up with an offer price?  
thanks for you help