possible commercial deal

[Vince Greenland]

I have a potential deal going on that i wanted some feed back on...The property is a 9,400 SF office building that has been vacant for 3 years. The current owners operated their computer business there for several years.
They are not interested in the real estate or any potential leasing so the marketing of the building is sub-par at best. I have been approached by a good government based tenant on their interest in the building. They want it and would like to lease it for us for a 10-yr first option triple net.
I have been negotiating with the owner and think we can get the building for $200k and would need to put another $200k into it for improvements to lease.
I have not started hard negotiations with leasee (waiting until i get control of building, but will not close until executed lease is in hand) but have casual discussion of $9/sf.
So we are looking at cap rates in high teens and a hefty cash flow with paying off the building in 10-yrs.
However, my concern is I really have no interest in the building other than the tenant. it is on a busy road just off of a major interchange, but the property is crammed in and has low visability. We do have about 200' of access on the busy road but it is under utilized.
I have always followed the philosphy of you buy based on the property,( location, location, location....)however this deal seems to good to pass up, but I still have reservations.
Our plan is bank on the 10-yr lease and pay the building off and see what happens after that which should minimize the risk. I have substantial other real estate holdings (multi-families with only one other commercial) to also rely on but still somewhat concerned over the commercial side of things.
Anyone have any thoughts?