There are also 16 at over £30k. The value is very dependent on the spec and modification history, particularly with early cars. The Matthewson's one was a very early example and almost certainly would need a range of upgrades to bring it up to a reasonable standard. These would easily cost in the region of £10k plus so a good basis but perhaps not quite the bargain it first appeared.
By the way, if you watch the follow up Mathewson's video where they are talking about it not making it's money due to missing out on the early chassis recall and free of charge replacement - there has never been a chassis recall for the M3W. For about 10 years MMC took a benevolent view on replacing chassis on early cars in the event of main tube cracking (which did not affect all cars). Last I heard they would make a substantial contribution to the cost but there can be a long lead time for a new chassis to be available.
I absolutely agree that spec and modification history effects the value of a car but 6 months ago even the 2012 models were £30k+ and the better cars were £40k+ Now there are only 3 M3W's at £40k, and you would have to be very extravigent to buy one of those when you compare what you can buy for far less.
