Moved to Bristol in 2006 and took a 20% pay cut. It was fine but after 2 years moved with work to Paris and 3 years later back to Hampshire. Last year my job in Hampshire ended as the company I worked for was broken up and sold. It became clear to me then that the gap between London salaries and those available outside London is wider than ever in my sector (financial services) so I've ended up working in London again and doing a long commute in. I couldn't find any jobs locally that paid more than 50% of London salaries. Might be different in different sectors though.