If Buffett wants to give his money away, I think he should.
$200,000 doesn't make someone rich.
Considering the average American makes around $50,000. $200,000 is well above average, and to many it would mean one is rich.
That being said, the wealthy in this country can deal with far higher taxation which they did in the 50's,60's,70's and 80's when the country was economically far better off.