very rough estimate, not sure

if it is accurate. I estimated based on a WSJ article, which says that by eliminating AMT, a household of four with $500k can save $20k.

"The impact of the change could be dramatic. A household of four with income of $500,000 could see its tax bill drop to $124,306 from $142,050 under current tax policies, according to an estimate by the nonpartisan Tax Foundation. That assumes full AMT repeal. Mr. Obama's budget without the AMT repeal would raise their taxes to $147,800" --WSJ