Lots of variables here.

Is it truly a cookie-cutter project, or do you want say in paint, light fixtures, framing, etc.Larger builders have less variability because they have systems and processes in place for hiring, building and management, but if you've ever bought a brand-new build you know that there are still defects, problems and variability in the final product.Hope that makes sense.

At the end of day, there's numerous variables to take into consideration. 

There are just too many variables and complexities.

Hey Bigger Pocketeers! Aspiring real estate investor here hoping to have a couple questions answered. I'm in my early 20's with a fairly good credit score looking to buy a duplex that's about 150k! Only problem is I h...

Maybe the explanation helps understand the reasoning for a 3 week window...like an appraisal window he's received or a contractor's schedule that is also variable (just random ideas). 

CapEx is a variable expense so, it's hard to pinpoint an exact percentage.

Mining is a niche within a volatile industry that has been a roller coaster ride over the past few years and also has some big variables that are uncontrollable: global regulation, hardware costs, technological advances in mining equipment and techniques, energy prices, and of course the price of bitcoin to name a few big ones. 

In my experience you are going to have a lot of variables that you will need to take into consideration while giving a blanket number.

Again, this is assuming you're doing 20% down.You can buy a dump for $150k, rehab and the ARV be $300k and you refinance your money out and basically got the property for free.There's so many variables.