Unfortunately, only one country left in the world where you can outright buy a citizenship...St. Kitts & Nevis.... $250K
I have always wanted to visit Nevis. If it was good enough for Alexander Hamilton, it is good enough for me. $250K is jump change if you have $10 million.
Obviously, I was joking about Cayman. However, I would research what countries do not share information with our IRS/Federal Govt. and move to one of those. I think you could move to any number of countries if you made the right campaign contribution. Ecuador also comes to mind.