Although its TV and therefor scripted this is the best of all the car restoration shows. They actually do a really good job of fixing up the cars to a very high standard without lots of shouting an bleeped out swearing of many other shows. Your right about not factoring in the labour, they replaced the chassis on a Morgan (very old fashioned British sports car with a wooden body on metal chassis - still in production!!) it took hundreds of hours and then had to sell it in the trade because they couldn't get retail money for it.
They really did buy the Boxster for £1000 (or at least that's what the script said) and advertised on Boxa.net in the uk for a project car. The guy basically gave it away as he could have got 3 or 4 times that amount all day.
I don't know what its like over there but second-hand stuff hear has very little value as everybody wants new and credit is easy to get (despite the economic situation). To give you an idea I can easily buy a genuine low miles for year (less than 70K) MY03 for less than £5K and an absolute immaculate 1 or 2 owner car for under £6K. But Porsche did sell a shed-load of 986's and that does reflect in the prices - people will pay for rare cars.
WD is required watching in our house and there is another series out soon and they are doing a Lamborghini.
This vid is quite fun - in a British kind of way
Wheelers Dealers Spoof / Parody - YouTube