Should I buy the other half?

[Alexis Marie]

I decided to turn my 1/2 duplex into a rental. I still have mortgage on it. The unit next to mine is vacant & owner asked me last year if I wanted to buy it, which I do want to. But the problem is the owner wanted $72k at that time, however value of duplex units on my street have been stagnant or depreciated over the years (according to county assessor info) and have sold for $50-62k in recent years. The condition of his unit is in bad shape & needs lots of repairs. I just asked him again today if he still wants to sell & he responded yes. So I asked him if he has an idea of the repair costs and I'm waiting on a response. My question is, how do I negotiate a realistic price with him considering the amount of repairs that will need to be done? Also, how do I get an estimate for repairs before I decide to buy it?