Once you have a good feeling for it, you can use shortcuts like a percentage based calculation.A lender will not mandate your replacement reserves unless you're working on a large commercial deal.

Stop trying to take shortcuts and stumbling your way through this.

Please don't over leverage yourself with what appears to be a short cut. 

If all you are doing is calling contractors from afar they will do bare minimum and take shortcuts to make it more profitable to them.

I did it because I knew this will be my ticket to riches beyond my wildest imagination... freedom, and bliss... and it paid off.So you can shortcut things, and with a bit of luck (a LOT of luck) you may make it... or you can follow a proven mathematical equation that WILL get you there.As a scientist and engineer, I can tell you that data, reliability, systems, and proof of concept ALWAYS is the better choice! 

There are no shortcuts when house flipping, so be sure to do your homework before investing in any real estate project.

So here is my process. 1- Open Zillow/ redfin or whatever, and type in a price range, 2 - Scan the states (sunbelt only for me) that have findings and pick the Citys that have properties meeting my criteria. 3- Check out the city on citydata.com (population trends, where they are at with state / Fed averages, etc... )4- If I like city-data then I will search and open the city's CFAR (Comprehensive Financial annual report) and see how they are doing with debt, reinvesting in the city, upcoming projects.. yada yada. 5- Once I got my city I will call 4-5 realtors and interview them (looking for ones that know how to "lift a skirt" of a home when looking at it, and can send video or photos)6- Call 3-4 PM companies and interview them, talk a bit about the market (rents/areas) and get some free info while interviewing them. it can be a lot of pre-work just to decide to dig in but I think it is worth it. 7- Remind myself to not overanalyze and stay away from Analysis paralysis.That's it that is my process... just interested in what anyone else's is, I feel I am too haphazard, I don't really crunch numbers, i just make sure the rent can cash flow (500 or more, pending funding terms) 

So it's a tricky scenario and one that you should not do haphazardly or lightly without knowing the implications of what you're doing.

In order to be a good agent, or a wise investor, there's no shortcut to putting in the time to learn the business.

It sounds like he has taken shortcuts and he wants to deflect some of the negative consequences off to you.