Best Buy and Future Shop have good return policies. They do seem to have some problems with putting returned items back on the shelf as unopened, though... For example, just recently I discovered my Xbox360 I had bought as brand new from FS several years ago is missing it's (behind-the-faceplate) warranty sticker - the most likely explanation being that someone carefully removed it then returned the unit.

Well, considering the tone in this discussion, I'm sure I'll get flamed, but... My dad recently bought some cryogenically treated cable and good connectors to make up a power cable for his CD player (a mid-range audiophile model, with integrated DAC). Didn't cost him $700, but it was in the $200-$300 range as I recall. When he told me, I thought he was nuts... I have an EE degree, and thought similarly to you about the results, but I was shocked that it made a large, obvious difference to the clarity of the audio. Everyone in our family can hear the difference, from me, the skeptical EE, my mom the musician, my sister who could care less about stereo stuff in general, to of course my dad with his probably dubious objectivity about the whole exercise.