I read the add borates section and created an (extremely ugly) spreadsheet (xls and xlsx files available)Borates calculation.zip to simplify the decision on which way to go (easy with poolproof) or still easy with the TFP system (20 mule borax and muriatic acid).
All you need to do is add the gallons of your pool in the green cell.
Costs are "hard coded" as per small print.
This works for a chlorine pool
It simply uses the calculation included in pool school
Any comment/feedback is welcome and I will be happy to update the file! My small contribution to a great forum!!