I own 4 STRs in Indy and have looked into the Nashville, IN market.

Hard to say if it’s a good deal without the most important piece of data, what is the fair market value? 

We always run a market analysis before making a purchase for ourselves or our investors.

Most of these course instructors aren't qualified to teach anything but the most elementary real estate concepts and try to make their courses more marketable by teaching concepts they have no business teaching. 

This is one of the main inherent risks with pre-construction, and the pre-construction market has cooled, and with impeding tariffs, there is some uncertainty around where prices will be in the coming months.One thing to clarify, are you looking to buy an investment property or a primary residence (or perhaps abit of both where you live in one unit and rent out the other)?

The current rent is much lower than the market rent.

At what point do you start marketing?

Both Charlotte and Raleigh are very strong growth markets, for all of the reasons that you mentioned.

I am considering a 12 unit multifamily property in my home market of Harrisburg, PA. 

In our market it is important to make sure they are a licensed broker, carry adequate GL and worker's comp (and name you as additional insured).