I bought in Battersea in 2009 and though the 2007/2009 crash is the only one I have directly experienced it seems property normally goes up fairly slowly and then you get the occasional crash like 1989/90 and 2007/2009.
When I bought nobody seemed to wish to buy and I though the Estate agent would offer me the hand of his daughter in marriage.
I did not If anything posh it was a 3 bedroom ex local being rented out and the landlord was worried about prices falling further , I was as well
However I got it for under the £250k threshold and rent saved plus the rent was higher than the mortgage cost.
Anyways Balham would be ideal for me from a commuting /social point of view .
Talking to vendors in 2009 then you could sense the panick and I think the only time to get a good deal is when the economy is potentially tanking, which from an employment / salary point of view is a two edged sword.
I could go to £550k in Balham but do not wish to do that if we get another crash in couple of years.
I do worry about local market though and wonder if Balham is still up and coming and might buck a general downturn at least in part.