Hire a pro and learn a lesson if you're not comfortable doing it yourself.

If you accounted conservatively for all your expenses and you are comfortable in that neighborhood it may be worth it.

These properties tend to come up most often, but its out of my comfort zone.    

I got my license five years ago so I can't remember how long it takes to get a seat at a testing site (if memory serves me correct I think a week or so).

The tenant will be in the drivers seat for this type of space.

If you still feel comfortable with those assumptions then the question becomes how comfortable do you feel that the sponsor is experienced and skilled enough to make those assumptions come true.In general you want someone who's going to be conservative with their numbers, someone who is going to under promise and over deliver.  

With my skill set I feel comfortable doing any job that isn't structural myself.

I've had an offer in the past to have a family member finance raw land for about $70-75k, which would put my comfortable budget closer to 80k assuming it works in my favor. 

If you know the market you want to invest in and feel comfortable with it, go for it.

That can be copied a given to the owner and make them more comfortable with your ability to close.Another thing you should consider selecting an office for its convenient location and have a minimal of distractions.