So would you suggest spending some time physically familiarizing myself with a various properties before getting into the deeper mathematical analysis and details?

i guess mathematically it MAY save you some money over the entire course of the loan, but sometimes there is more value then living in the now rather then the calculated savings over the loan...

@Carter CrowleyThis is truly a mathematical question: If the after tax return from re-investing your retained earnings is greater than the debt service rate on your present financing, then reinvest.  

I still don't understand why you're still so insistent on the debt thing -- your comment "less debt enables you to help others" really doesn't resonate with me (nor does it make mathematical sense).If I have a $10M net-worth with $1M in debt and you have a $1000 net worth with no debt, who is in a better position to help people?

It's mathematically impossible for prices to go up every year. 

As I was poking around at the relationships between jobs and potential predictors of job losses, I started looking at a mathematical representation of something less quantitative, that we are all familiar with.

That's why I never trust website estimates, they just have a mathematical formula that spits out random numbers, it generates almost the same value when you have a 200k interior and 30k interior.

Mathematically challenged?

Specifically:value = rent / 0.01 (estimated via the 1% rule)NOI = 12 * rent * 0.5 (estimated via the 50% rule)cap rate = NOI / value = (12 * rent * 0.5) / (rent / 0.01) = 12 * 0.5 / (1 / 0.01) = 6 * 0.01 = 0.06In other words, combining the 1% rule and the 50% rule is the mathematically the same as assuming a 6% cap rate for residential.

My advise would be to focus on analysing a business thoroughly and not quickly before making an investment decision.Naturally there specifics to different industries which one needs to know to evaluate the quality of a revenue stream; the reasonableness of operating expenses; and whether the debt load being carried is appropriate, but the mathematical callisthenics are the same.Screening a property, or business, to see whether it warrants further examination is a different matter.