If third party, typical management fee is 10% and leasing commissions range, but commonly 1 mo rent for new leases and 1/2 mo rent for renewals.  

The problem is the FHA loan limits (~$1.2M and $1.5M respectively for a 3 and 4 family) and my available cash put these properties out of my price range (prices range from $1.3 - $1.8 in the areas I am looking at). 

Southern side of Cape Coral is easily seeing most lots in the $50,000+ range, whereas the Northern side could still be as low as $8,000

So I'm thinking that the total will be in the mid-20 range.

Your in the 40 inch range.  5.5 acres, I would budget about $15,000.7. 

The loan will end up being in the 900k-1m range.

My reasoning is that your income may not be sufficient to pay for both the mortgage and rent for an extended time where you don’t have a Tennant during remodeling or someone isn’t paying their rent.

Then the ADR you can do the same with analyzing comps for low-mid-high assumptions and create a range there too.

FHA is really useful if maybe your credit is slightly below conventional guidelines, or maybe your DTI is just outside the conventional range.

A price that was actually in the range of what I already knew I could pay.