What is the best way to get 6 unit apartment under contract?

[Terrance Merck]

I met with a real estate agent on a 6 unit 1 bed 1 bath apartment building. I am informed that the owner is the original owner of building and has had it since 1986. Agent informed that the owner has been hands off for about 8 years, his health is not so good, and pretty much just wants out. It is a grade C apartment,  rent between $375 $425, is half occupied and could stand some upgrades. I haven't made an offer and would like advice on the best course of action to get property under contract.  It has been on market for a few months and the asking price is $125000, but the owner is motivated and flexible. I was thinking of either  getting property under contract for $70000 and either wholesaling property or rehab, stabilize and maintain rent at 400- 450 mark. All thoughts comments and suggestions are welcome.

Thanks in advance