I once considered relocating with the same company to a similar role in London. The base pay in London is lower, and the marginal tax rates are high, but overall cost of living isn't too terribly far off (compared to the SF Bay Area), and doing calculations like these it seemed that while it would be something of a step down total compensation-wise, it wasn't nearly as large of one as it at first seemed. I didn't make the jump, but actually doing the math made it seem a lot more reasonable than it did at the outset.