http://dbaron.org/views/taxes-2007.html claims that in California, total marginal tax rate including SS but excluding private health insurance is around 40%, depending on the income. So with some room for retirement and health insurance, yes 50% is about the same or less as in most of Western Europe (the 40% quoted for Germany is only income tax, you'd need to add the mandatory part of the health insurance to it, the local taxes and of course the sales tax which is 19 to 21%; I don't think it ever goes above 10% in California). Oh and 'capital taxes', (not even 'capital gains taxes', which you have to pay too, I'm talking tax on things that you own and on which you've already paid tax before).

Yes California is expensive, tax-wise, but it's not as expensive as most places in Europe. Other places in the US are much cheaper.