Ludwig, I can't really see any relevant comparison between my dealings with a tradesman and the Revenue's dealings with Jimmy Carr. For a start, I very much doubt that he - who did nothing illegal anyway - splurged the 'saved' 99% of his 'imaginary' tax-bill in a oncer, unless, of course, he bought a private jet or some such!
My earlier comment about 'fags and whisky' was in jest, as I have not smoked for 15 years; however, I definitely am partial to malt whisky and real ale, so I would have blown my 'saved' £200 pretty rapidly! Consequently, the government would have largely regained via alcohol tax the 'lost' - because untaxed - £200 income of the tradesman.