London Rent Map
The average monthly rent for each tube stop. See a HUGE version here.
I moved out of Brixton/Clapham North in about 2002, when a two bedroom flat, infested with mice and cockroaches (not to mention the drug den opposite us and the shootings on our doorstep) was £800. Not sure I'd cough up over a grand for that, but there was excellent jerk chicken nearby.