The question really is if it were designed to more refined appearance standards, would that make a noticeable difference or would it not. That'd be an awesome A/B test. And, logically, if I were Patrick, I would set up a separate website with a polished design (like the "front page of Dribbble" polished, not "the best a programmer can do" polished) and pose it as a competitor. It'd be interesting to see if it would borrow people from the original BCC site or if it would pick up new customers.
Shouldn't be an expensive experiment to run too, the cost is mostly in design and that's up to 5K tops.
It's pretty difficult to see the world through your users' eyes instead of your own, but Patrick seems to do this on a regular basis, which I find quite inspiring.
This isn't a negative criticism, but it's a point of interest to me to keep reminding myself that what I want and expect when I go online and buy something can often be different to what the customer actually wants or responds to.
You give frequent detailed and excellent information, thanks for keeping it up with no obvious benefit to yourself!