Interviewing recently (in the UK) I find the same to be true. Although we only had 1 woman in the interviews, she was double the asking price of the other candidates we were getting in that are male.

I can't say for certain why this is, maybe it was the role we were hiring for? The male candidates were more or less happy to move to us for the same price they are currently being paid where the woman actually asked for double what we were willing to pay for much less experience than the males.