Commuting times and housing costs compared in eight major cities
There's probably a pay wall there, and in any case, Sydenham doesn't appear on the graphic they have for London, so I thought I'd add it

It's not quite right - size reflects cost of commute, and with some of Dulwich in Zone 2, the circle for Sydenham should be the same size or bigger than Dulwich, and I think it should be directly under, since commute times are I think the same - at least they were when I checked with CityMapper.
But the big difference, of course is price. For this, I measured the floor space of my house, which I'd never done before - I'd be interested to know how many other people know their floor space, rather than just how many bedrooms, and took the current price estimate from Zoopla, and current $ exchange rate to get $579 per sq. foot.
So property in Sydenham still is a bargain compared with the rest of London.
Existing SE London property owners, fed up with disappointing returns on their investment, can do something about it while simultaneously signalling how virtuous they are, by signing this 38 degrees petition to stop a proposed high rise development in Catford
STOP 19 STOREY TOWER ON CATFORD GREEN