Then ended up having to pour a 12" concrete wall against the original block, adding and additional $7000 to my rehab. 

Long story short she put a house on Craigslist for rent and then noticed a rogue ad a week or two later with different contact info--offering to rent her house at a different price. 

Do drive bye's first so you can see the neighborhood, the conditions of the roof, dead/dieing trees, driveway concrete issues, etc. before asking your agent to set up a showing. 

That way, you would have a concrete budget to consider as you explore purchasing a home.

A concrete and committed marketing plan will generate leads and quality deals.

The following is a partial list of things that wear out or become outdated over time and eventually need to be replaced for every property:-Roof-Siding-Hot water tank-Furnace-A/C system-Electrical system-Plumbing system (inside)-Sewer service line-Water service line-Any concrete exposed to the elements (sidewalks/porches)-WindowsIf you calculate the cost of replacing each of those items and divide them by the expected useful life, then sum that up, you'll come up with a monthly amount that you can expect to spend on capex over the long term.

I live in a town where the 1% deals are not easy to create, and even more difficult and rare to just stumble upon, but they absolutely are out there.Some 1% deals are residences, some are parking lots, and some are a flat concrete pad with cell-towers disguised as flag poles.If you were to compare every 1% deal across a tough town you'd probably find lots of creative angles unique to each deal.   

If you are buying and holding then the nets to work into your analyses would be: (1) mortgage, (2) maintenance fees, (3) property taxes, (4) homeowners insurance, (5) water bill, (6) property manager if you do not intend to manage it yourself, and (7) future property maintenance, suchas roof & painting, and concrete.  

To be fair they were new construction brick with concrete scored floors..

At the moment I don't have a concrete answer to your question.