And while I am not against investing in Mexico, DR or Columbia (I've heard some great things...) there is a sweet spot as an American investing in an area that I don't need a passport to travel to, and that uses the same currency, and feels safer because it's part of the US. 

The sweet spot is 25% down but products were showing with 10-20%. 

Plus, the tax advantages of STRs can be pretty sweet.

I know Tesla has a pretty sweet setup, but they are usually set up in common areas not in each garage. 

What's the sweet spot?

Based on your calculation, you retire in 10 years at the age of 49 which is much better than the average person.You will likely have a bunch of paid off houses and a healthy 401k balance.Seems like a sweet analysis.I am happy for you.

I have seen the sweet spot for ARV in Jax SFH lately have been in the $125k-$175k range.

Many people buy in larger cities like this because the paper cash flow looks sweet, but the reality of it, across the board right now - good cash flow equals lower neighborhood class, more variable tenancies, and tons of hidden capital expenditures.

A good income wouldn't be as sweet with no access to good debt. 

And that extra payment is oh so sweet boosting your net income.