Related somewhat: Atlanta median income down MARTA's Red line (travels North to South) http://news.wabe.org/post/atlanta-biggest-gap-between-rich-a...
And here's one for London: https://www.thrillist.com/lifestyle/london/london-undergroun... Direct link to large-scale map: http://assets3.thrillist.com/v1/image/1560005 Note we tend to think of flats in terms of number of bedrooms. Hatton Cross is right next to Heathrow airport, if you're wondering why it is so cheap.
This map has areas of london by square foot for a closer comparison, but isn't by tube stops. Looks like we are more expensive than the bay area, if you go by area - We live in much smaller houses than in America, I believe