How much does it pay, relatively? The last time I looked into jobs in the UK and in Europe, I could make more money flipping burgers in the US.

I'm seeing offers of 150k GBP or more in London, no idea if they're real though.

Depends on how you look at it. For example, the average salary in my Central European country is about 27k USD per year. I work in an IT/telco business and make about a double that. While it may sound very low for US standards, I own a house, a car, and go for a few non-lavish vacations each year with my family (wife makes about a third of my pay). I don't stress about health expenses, and have a good small town community just outside the capital city. People who work in senior management in tech, or work for international corporations can make upwards of 120k yearly, and will have a very comfortable life where I'm at. It can't be directly compared I suppose.