Yes the London market is a bit nuts, but if you're paying anything close to 25k/year (that's 480/week!) for a 2 bed in a "not great" part of London then either you have very high standards or you're being seriously ripped off.

For example see what this gets you N1, a pretty central and desirable postcode: http://www.nestoria.co.uk/n1/property/rent/bedrooms-2/maxpri...