Thoughts on buying equity in high-equity tax delinquent homes?

[Nikhil Nirmel]

Looking for an evaluation of my proposed strategy.

- Identify tax delinquent properties. Figure out which of them are owned free & clear or have low mortgage balances.

- Make an offer to their owners like this. e.g. Property worth $200k, they owe $15k. I say, I'll give you $50k today, you pay off your tax debt, and you give me 25% of what you eventually sell the property for plus $3000 or an additional 1.5% of the eventual sale price per year. Homeowner wins because their debt is paid, and they have the option of making no payments. The holder of the tax debt - whether the county or an investor - wins because they get paid. And I win because I get income and appreciation from a property I don't manage. 

Has this been tried? Where could I go wrong?

Thanks!