We both contribute equally, and we live in Madrid where cost of living is relatively low. Two people living together can live on £9K / year here no problem (that's about 1000 euros / month each). That said, I do have savings that I've been eating into.

I've never felt the need for lots of money to be happy. What I really value is being able to do interesting work that I'm proud of. So I'm very motivated to make money to the extent that it provides freedom to work on interesting things. And perhaps even to contract people to help out. I guess that's a philosophy shared by many of the people here.