HELP!!! Tax assessed value versus actual value

[Marie S.]

I'm in the middle of a deal. I can't get on the same page with the sellers. They seem to think the property is worth a lot more than I perceive. The tax assessed value $22,000 less than the listing price. There are not real comps in the area as all of the multi family units are 2bd rm where as this property has 1 bedroom units. I understand that they may want money for the work that they put into the place, but the work they put in didn't increase the value from when they purchased it. (They purchased it $39,000 less than listing)

I can't afford to lose the place as I need somewhere to live, but I don't want to get duped into paying more than I should. How do I approach this deal?
Is the County Tax assessed value irrelevant in this? How do I determine my next move with no real comps?