Definitely go check out the FilePlace and download a couple calculators so you can start messing with numbers.

We are buy and hold investors, so we won't touch those.We make a spreadsheet for every property we're interested in, then calculate our max "all in" amount that will give us the rate of return we are seeking.  

LOL, does it seem like I need Brandon's book on small multi-family deals or use a calculator?

Or is it the case that the way the calculate the total payoff is different than the way the calculate the reinstatement?  

So we're now able to calculate just how much we are saving them, and will probably factor that into future rent increases.

I understand calculating ROI (my background is finance from DePaul)2.

I'm using the rental property calculator on BP. 

Never had any major issues as a result, just factor it into your calculations/pro-forma to analyze for the added expense appropriately.As for what that expense is, it's all market specific of course.  

I got to look at a property today that I believe has some potential - running the numbers through the BP calculator right now.

Are you sure you measured/calculated correctly?