You don’t get that type of return in your STRs straight up or risk/hassle adjusted.Industrial properties the demand analysis is always local and not nationwide.  

Of course there could be some other local businesses that might would want to use or share a couple of the offices that would possibly increase revenue. 

But you knew the local landfill/trash incineration company had been given the ok to build a massive facility in 3 years.

I'll just add a local perspective: North Atlanta ie city, Sandy Springs, or Alpharetta?

Your best bet is to find and contact all of the top local wholesalers and go to work for one of them and see what they do right and wrong and see if it's even a business you like.

Consult with local RE agents for a more realistic perspective.

A friend of mine and I went to meet him at a local golf course and then we talked more about the opportunity over lunch.

If your really needed it one could also consider hard money though that will come with higher rates and getting someone to give you 300k first time might be harder than just getting loan then you could refinance it later.Since your a high net worth person I would also try talking to local/regional and even big bank lenders.

I'm looking to connect with local investors, agents, lenders, property managers and contractors who have experience in these areas. :-) 

@Robert Kline, I would start by talking with your local building department.