Scalito had major conflict-of-interest issue

Another ethically challenged Bush appointee according to the Washington Post:

Three years ago Alito drew conflict-of-interest accusations after he upheld a lower court's dismissal of a lawsuit against the Vanguard Group. Alito had hundreds of thousands of dollars invested with the mutual fund company at the time. He denied doing anything improper but recused himself from further involvement in the case.

Hundreds of thousands of dollars and it didn't raise ethical concerns for him. So how much did he have to have invested with Vanguard before it became a conflict-of-interest? This should get an enormous amount of scrutiny.