That equity becomes the cash input to the equation of some new deal's estimate of cash on cash ROI.

one of the seller's motivations is to avoid a big captial gains hit - so I'll have to look into how that fits into the equation.

The numbers I'm pulling are north of $3000/month which would equate in solid cash on cash, and cash flow with 25% down on $489k property.This home was built in 1925 but very updated across the board from interior, exterior and major things like new roof in 2012, new AC in 2015, and new plumbing / electrical in 2017 - BUT, this was built in 1925 and still at the back of my head.

Assuming the average household size of 2.47 per the census data for the Austin MSA, that equates to 27,205 new households transplanted.  

Eventually, to make the #s work on new construction, I got my GC license to remove the cost and dependency from the equation. 

Banks require 20-25% down for a reason, it equates to less risk.

A full futures contract is 110k ft board which equates to ~$14k 8ft 2x4's.

Tough to know without that part of the equation.

You can't calculate a flip when you don't know really how much everything costs and what to look for and there is no set x if y equation because it's all predicated on what you can buy it for, how much the rehab will cost, and most importantly, what the realistic ARV is when you are done.

Another way to look at it would be to know what your currently pay in rent per month, and then use that amount as a starting point within a mortgage calculator (for example, if you pay $1,500/month in rent, then that equates roughly to a $320K loan amount on a 30yr mortgage.