I'm thinking that detail caprate/COCR calculations can be done after the basic filtering. 

Check all your HVAC filters as it is unlikely that any of these have been changed

In fact, there are many properties being listed that barely cash flow as far as I can tell, depending on the accuracy of the utilities/insurance/maintenance/tax estimates I'm using.I've analyzed around 25 properties so far (after filtering through many more) and ones worth considering usually cash flow between $150-$600.

You need to take a deep breath...

Account Closed, filter the price graph to "median sale price" Zillow.

If you have a good screening process, you can filter out the bad apples. 

You can use "rules" as a quick & dirty to quickly filter properties, but if you use a rule that most of the country can't fulfill anyway you are either going to find yourself with some real humdinger properties or with no deals at all.

Honestly, in my experience filtering your investments via an LLC is the way to go.

Go to craigslist, filter by Real Estate for sale by owner and call the first page (if they have a phone number).

My system uses one of those big filters that are only replaced every 3-6 months (not your standard 1" filters), and they cost like $30 a pop.