Tom, for your example you picked 30%. It can go much higer, in fact I have seen instances where it has been in excess of 40% (AMT can get you there!). So, your example is on the conservative side in my view.
One choice I am trying to balance these days, is to sell off some of the stocks that have fallen while I can still take short term losses to offset my gains. Once they become long term, there is only half the tax benefit for selling these guys.
tab