Shopping online for home theater cables should be one of those activities that carries the standard amusement park disclaimer. You know the type: pregnant women, people with heart problems or back ailments, etc., should not ride this ride. If you don't believe me, go check out the prices for things like HDMI cables, but be sure that you empty your pockets of loose change and let someone else in line hold your sunglasses.
A quick survey of the web sites of three large electronics retailers showed that the average price for a six foot HDMI cable is about $57. Oops! There goes your hat. It sailed right down toward the unloading area of the Log Jammer.
A little bit of Googling revealed an excellent article from CNET on HDMI cables. Of particular interest was this sentence:
CNET strongly recommends cheap HDMI cables widely available from online retailers instead of the expensive counterparts sold in your local electronics store.
To sum up, these cables are transmitting a digital signal, and digital either works or it doesn't. The old RCA-style connectors on plain-jane analog cables were susceptible to RF interference but these new digital cables don't share that weakness.
The article goes on to recommend some places to buy cables online, and I was able to purchase three of them for $15 including shipping. That's quite a difference in price, something like 91% off.