How much income do you need to be happy?

I need to be able to live in a nice house which I own, pay my bills, send my kids to school (when I have them), eat whatever I want and retire early. Did I leave anything out? That should come about £100,000 p.a. after tax :) 

More is always better :). But to be honest I have disconnected happiness from money directly. Instead I ask what makes me happy and how does money enable that