.- Current ROI for the Middletown duplex =         [($1325 x 12) - ($450 x 12) - (130 x 12)] / $25,400 = 35% ROIYikes...this formula is missing two huge pieces of the puzzle - OpEx and CapEx.  

If it comes back positive you should be able to get the property for a song. 

Closing a line lowers the denominator in that formula) all the while search for deals with seller financing and partners with $.

It sounds to me like they just looked at tax value or applied some generic dollar per square foot formula.

Do you use a formula or just throw in ball park figures?  

You are probably looking at a HML @ 10% with 2 points that you need to work into the formula.  

Who of us (myself included) hasn’t put together a quick spreadsheet only to discover — sometimes a little later than we would like — that a typo in a formula has led to unintended results?

I know that when you do the formulas for a new purchase, this is true.

@Brendon Woirhaye is there a formula that would determine it's value after I know the market rates for rent?

I was looking for the magic formula to quick riches.