Exactly. I've got "2.4 family" friends who live in Clapham and Walthamstow, earn about £60K between them and live comfortably. Would they like to have £500K salaries? Of course. Do they need them? Of course not.
A 3.5-bed family home in Clapham is around £1m, a 4% payment on which would consume their entire net income!
source - http://www.londonpropertywatch.co.uk/avg_prices.html