MSD

True story:

I went with two of my friends to the grand opening of PC Richards. I had recently purchased several 6' HDMI cables from HDMI Cable, Home Theater Accessories, HDMI Products, Cables, Adapters, Video/Audio Switch, Networking, USB, Firewire, Printer Toner, and more! (you are a damn fool if a cable is available there and you buy it elsewhere) for $7 each (as of a few weeks ago, they were down to $1.45) I picked up a Monster brand HDMI cable of the same length priced at $79.99, looked at the back, and saw their comparison; my exact words were "oh my God, there's a more expensive version of this cable." On my way out I spotted the premium cable and it was $159.99

At this point, a salesman walked over and asked if he could help; I told him I was just looking at the cables and marveling at the prices, he responded that "Oh, I heard you say 'more expensive' and thought I could help." (I'm not making this up, and I can't blame him because when I worked at Radio Shack on commission I actually had a customer ask if I had something "a little more expensive.")

I pointed out that I had bought a functionally identical cable for less than 10% of what they were charging and he gladly explained to me that inferior cheap cables tend to have internal solder points that aren't exactly the same size, so the signal doesn't reach all the pins of the cable at the same time. I politely excused myself to the disappointment of my friends who were eager to see me debate the sales guy, especially since each of us had a couple of drinks before heading out. Once we were a few feet away but still in earshot of him, I told them "that man just told me something that directly contradicts what I know about the speed of light. Him versus Einstein, I know who my money is on."

I have not gone back to PC Richards since then.