The question would be the sustainability of the overall economy and job market. 

Is there enough of a data set of these tax sales In your area, during the recent economy, to come up with a statistical likelihood that is reliable??????

Market and economy added value while I maintained the residence to high standards.

With this technique, you can go to 80% currently (and 85% in a more "normal" economy). 

I can't imagine another sector of the economy where anything like my story is even possible. 

- vandalism- unstable economy - and many other problems of an impoverished countryI'm sure once you have a good team (broker, agent, lawyer, insurance broker, contractor, prop.mgr) that you can trust, it's all doable, but building that might take time and money and physical presence.

Real Estate will sharpen your instincts and make you stronger but you definitely have to stick with it.

Different circumstances, different economies, different geographical areas and different players all have tremendous influence on the success or failure of a strategy , or tactic.  

Where are areas that have a diversified economy?

Certain deals/funds will have stronger cashflow vs others are stronger upside.