not perfect but for existing construction, it is about as accurate as possible.  

Honestly, if you are accurate with your rehab cost estimate and your ARV is realistic, you shouldnt need more than a couple showings (one even).

Assuming they are accurate, your total investment of $501k is a very risky 84% of the ARV.

It's time to put the hand saw behind you. it's called "compound cut". as long as u know how to use it to make accurate cuts,  they are all about the same.  

I have comprehensive lists I have typed out for him meeting each trade to get an accurate bid.

@Tim Puffer, My inputs well undoubtedly get more detailed and "accurate" as I get better at this, but as a practical expediant, I used some percentages of revenue and purchase price to estimate certain costs.

These have been pretty hard to find and work with, but once you start using them, they get easier.We have always found them to be pretty accurate when properly adjusted for the park/community they are in so your comment puzzles me.

Obviously can get more detailed to accurately assess ARV/repairs... and include things like school districts, crime, levels of rehab needed (high end/low end), etc...I want to be an expert in this area, show me the way!!

I've audited their courses and they have very well organized and accurate content.

MLS is great source for all properties that are for sale , you need to make low ball offers every day like 65% minus repairs and see what could be accepted,  right . submitting 20,30 offers daily is big task and must be automated somehow .if you would submit 100 ridiculous offers you might get one accepted which is not bad , but you need this machine first and system that produce accurate offers based on ARV, estimated repairs or upgrade based on square feet.