If it was me, I'd look at it this way:1) Paperwork: I can hire an attorney at an hourly rate to write up a purchase contract, etc. 

You start with a purchase and sale agreement and reduce everything to writing.

Quote from @Jonathan Weinberger: Hey BP community, Every so often I enjoy writing about my investing experience here.

Before any mediated settlement is binding, the parties to the dispute must agree to the settlement, in writing.

Data point: we have a long-term rental in a popular STR neighborhood listed through Zillow right now.Every person who writes asking to do some sort of arbitrage is blocked by the Zillow platform.I don't even have to say "no thank you anymore."  

On the other hand, if you write something into the lease that you agree upon, it should be fine, but that may turn off many prospects IMO.

Ideally, you want something in writing, but that is probably unlikely since no one will want to stand behind a not-yet-final number.

Quote from @Fernando Corona: @Erik Estrada I actually wrote a blog on the topic and will continue to write about it.

I use a spreadsheet I developed to determine my entry costs, carrying costs, cash flow, tax write offs, appreciation and exit costs.

I won't just write them all here but I highly recommend contacting a qualified 1031 intermediary to walk you through the process.