Circuit City is all about choice. If the story from one customer is true, when you buy a brand new machine there, you can either get hit for an undisclosed repair fee at the till or take it home broken.
The customer says he was lucky to spot the $40 charge on his receipt. The rationale given was that the model sold required a BIOS update to work properly, even though it seemed to already work just fine. From The Consumerist:
Regardless of the fact that Vista booted up just fine with out the update, he was more disturbed with the fact that Circuit City would sell him a computer that they knew didn't work or so they say. Unfortunately, he was short on time and did not press the issue in the store.
And that's exactly why they do it.