Our ever so friendly local paper the Meaning Evil's take on Darrent Bent. He cost us £568,000 per goal. Not, he saved Villa from certain relegation in at least one if not two seasons potentially costing them millions and years of relative oblivion.
Can't be bothered to find out the details or work it out but I would take a guess that we broke even on Bent if you balanced their argument with the money lost from being relegated (even if we had been promoted the year after, big 'if' though).
I wonder how much Zigic's goals cost the shower down the road. Even before adding the cost of relegation (which was mostly due to the goals he failed to score), I bet there is not much in it. Who signed him? D'oh, we went and employed him and ended up with long term drain on finances in N'Zogbia, Given and Hutton but that's a different story.