BiggerPockets can be a great resource, and I know there's tons of information available on the Fort Myers market specifically.

If the property appraises at $500K, 25% higher than purchase price, either because you bought it for less or due to market appreciation, then you essentially get all your $100K back.  

We have also had great success in Madison county, great potential!

If you do a case study also consider what market appreciation and mortgage paydown would occur in both scenarios.

This is often a losing proposition for the seller, unfortunately.Granted - when a house in in disrepair and would be hard to market otherwise, it is a path forward for the seller.  

How much it rents for is not determined by what you'd need to make it a good investment, it is determined by the market. 

Currently, the market is still short on supply so when putting in offers you need to put on the 'seller' hat and think what they would want.

For example, I know of a deal in Reno, NV where all the records were still on paper, and the owners didn’t even know the rents people were paying.When I’m evaluating multifamily properties for clients around the Reno area, I calculate current, market, and proforma rents.

Since you're planning to buy your first multifamily unit, I suggest looking into markets that have great macroeconomics with growing population and jobs just like Columbus OH.

The NOLA rental market, especially for the more expensive neighborhoods like the one my rental is in, has been slow.