Calculating the ROI for a flip, as in Brandon Turner's excel file

[Brandon E Barker]

Hello!

After reading Brandon Turner's book on Rental Property Investing, I went to checkout his Investment Calculator spreadsheet. The ROI (row 59) is calculated before annualization as (profit)/(down payment) = B58/B39, but it seems like to me it should be (profit/(total money in the deal) = B58/B56. Actually, I can perhaps see how this isn't quite right either, since the loan value maybe shouldn't be in the denominator. But, it at least seems like some other value should be in the denominator, like the point value added to the loan (B44), realtor fee.

And related to this last point, shouldn't the total money in the deal be greater, and include "total debits at closing" (B53)? These seem like expenses related to the deal as well.

A minor related question, for B52 ("their closing costs"), why is this included in our money in the deal, and thus in the equation for our total profit? It seems like we shouldn't normally be paying the seller's closing costs?

Thanks for answering these newbie questions, and sorry if I'm already forgetting obvious points from the book.