And, depending on your market( I don't know about Memphis) "R"ents  are rising but may not have yet caught up enough to cover those rising costs and the larger amount you need to "R"efinance  to cover those costs.

This will also allow me to capture the larger equity upfront.

Here is an interactive map that I feel gives some insight: https://www.nytimes.com/intera...I do believe that in 20-30 years, Midwest markets like Cleveland, Detroit and Pittsburgh will be even more desirable given their proximity to fresh water and they all have existing infrastructure to support larger populations. 

Using a price per SF will have you way off on one of these two.The only way to do it is to get yourself a spreadsheet with all the line item tasks possible.

I would buy a slightly larger home and turn your current home into a rental.

What I would do is call local credit unions instead of larger banks.

We also have a couple of larger projects looming such as a retention wall (we are on a canal with ocean access), a new driveway, and completion of a fence.

The higher loan amount of the owner occupant is ballpark a wash with the higher rate of the investor, who is borrowing less due to the larger down payment.You can scale it up and down easily.

@Ryan JohnsonIndustry, lifestyle, government, and spillover from larger nearby towns and states usually drive population growth.

Take now larger pool of capital to buy a better deal or invest in two deals.In many cases, buy and hold doesn't equate to scaling fast, especially on your own.