Is it really from land reg data though? We're looking for a buy-to-let right now, and yes there are deals to be had, but the majority of family sized homes aren't around the 80k mark. i'd say that average is quite low in compared to the reality.
Actually, if you'd care to check the BBC source, you will see that it is the Land Registry too.
However, the BBC quotes the land reg's raw data using the arithmetic mean rather than the geometric mean that the Land Reg quotes in it's adjusted data. Meaning that the BBC figure is somewhat misleading, because it doesn't account for the warping caused by peripheral anomalies (high & low end property sales).
You'd be better checking the Land Registry data here:
I blame firstly the banks for extending credit to people who couldn't afford to pay them back long term, with self-cert loans etc in an attempt to boost the over-saturated mortgage market from 2003 onwards to stop prices faltering then, helping cause the boom.
Yes I'm afraid the op is right about the BBC's figures being distorted. They constantly quote the non-adjusted figure, which is useless, eg the Land Registry's actual published figure for av. house prices in UK is about £100k below the BBC's over-inflated figure.
When house prices crashed the BBC soon stopped updating the House Prices page as if they didn't want anyone to know that prices were dropping. You can actually go & check this is true on waybackmachine, the website that caches old pages (now that they've updated the cache).
The BBC stopped updating the house prices page for well over a year. When Prices started going up again, then they started updating it again.