But that function guesses and iterates to do this calculation, and does not converge with those terms. 

I think I've figured out my plan of action in these iterative steps for purchasing another single family home. 

A unique script has to be written, for each county, to iterate through ALL of the accounts, and compiling the data in a database, which can then be queried for accounts which match your criteria.Iterating through all of the accounts requires exploiting the county's online property tax search.

As we iterate through this CRM we want to be able to manage lead generation, scheduling of tours, deposits, leasing and then seamlessly transitioning that lead into a renter in our management platform automating as much of this process as possible. 

I am a Agile and lean guru.

. $700 each 6-month iteration), but will reduce my mortgage interest by over $200k!

They have recently spring forth as two new iterations/websites to try to escape their reputation and keep ripping off investors- The other two current names are Real Estate Federal, and Real Estate Leads and Appointments.

Agile has a real estate specific free version I've dabbled with.

The plan document is the key to give you control and agility.

My reaction will be to simply continue to run our business with speed, agility and adaptability.