You would be able to sell it you would probably have to accept it just isn't worth what you would like it to be.
You can't argue with a straight face that getting close to 600,000 pounds doesn't make you a 'have' compared to those who don't.
Your class is irrelevant there is no entitlement to inherited property wealth at someone elses expense (and lets face it when your working class parents didn't buy their house it would have been at the trad 3 times one salary etc etc)
House prices are one great big ponzi scheme and the person who 'pays' will be the person left holding the mortgage not hard working working class people who happened to buy when life was different!
(I do accept my views on London property prices are somewhat towards one end of the spectrum)
oh and loads of circa 1,000,000 houses round here are poorly maintained piles of s&^t with people living downstairs/virtually confined to one room because for a whole variety of reasons they don't move)
all IMHO obviously