It sounds like a good deal. I own a couple of commerical places right now. Cost really doesn't matter if the numbers work. It sounds like property values are on the way up and the rental income will cover most of the payments. Also need to consider the cost of property taxes and insurance and the inevatiable repairs. When was the last time the HVAC was checked?
Another thing to consider, If you are not around to keep an eye on the property you need some one that can, a friend, trusted family member or a management company. What is the interest rate the current owner will give you? If he dies, do you make payments to the estate, his heirs, or is the loan due? Food for thought.
Mark