It seems like a very simple Excel spreadsheet should solve the analysis concerns in regards to the number of hours spent.

You can win them over though. 

Generally speaking, the people who win lawsuits are those who have the best documentary evidence. 

House hacking - renting out a portion of your primary residence to cover part of, all, or more than your mortgage payment - is an excellent strategy for investors of all experience levels to reduce or even eliminate their housing expenses and begin to generate cash flow right where they live.

That becomes a win-win because you can offer it at a big discount because you have no rehab and no realtor fees, and they can buy a house they know and love.You may want to consider the tax implications.  

Say if Fannie Mae  bought the property for 250K, what are the chances of us winning if we make an offer for 260K.

Rental real estate is traditionally an excellent medium-to-long-term investment from a financial standpoint.

And before that quickbooks/excel.  

Hi Edward, you can have a look at my file place on BP, I have a few excel spreadsheets that may help you in your real estate investing journey (to analyze rental properties, BRRRR, etc).

Learn, connect, and then see how you can use your expertise to be a win-win for investors.