I track everything at the "buy" on a spreadsheet as far as income, expenses, CoC return, ROI and have another spreadsheet to estimate and track all rehab costs.

I know a lot of people who do it, I would ask what is your exit. for example we have done it when we were doing some renovations and had a line of credit as well that we were going to transfer the cost too.

I may get flack for saying this but there is a wealth of information available at little or no cost and local REIGs that can teach you about your local market. 

The cost to get the ADU rent ready and fully permitted was $25,000, most of which was the exterior landscaping.

Appreciation there is low, rents are low, and assuming maintenance as a fixed cost (for example, a hot water heater costs $450 from Lowes in Allentown, $450 from Lowes in Scranton, installation takes the same time, and labor costs aren't all that different), the ROI isn't great.

A lighted inspection camera/borescope costs fifty bucks. 

The goal is highest rent for lowest investment cost and lowest maintenance.

You might win, but it may cost you money to win and hire a lawyer to defend lawsuits. 

What did it cost?

Once you begin to generate leads that fit their recent purchases/want to buy, run the numbers based on the ARV after repair value for after when they develop/fix n flip and subtract cost of build/repair, your assignment fee, and the original cost of the contract.