First of all, I have to say when HDMI cables first hit the stores, they were a RIP-OFF. It was like the electrical chain stores, on both sides of the Atlantic I hasten to add, were selling the TVs pretty much at cost, knowing they'd make a killing on the "must have" 100-dollar (or 100-quid) HDMI cables needed to connect up all your new gear, probably making them even more profit than selling the all-but-pointless extended warranties. As an aside my brother used to work for Comet in the 1980s. He hold me they made diddly-squat on the appliances and all the profits were in the extended warranty sales.
Nowadays, HDMI cables aren't the ripoff they once were, generally speaking, but experience the hard way has taught me it's the terminations, not the cables themselves, you should be looking at. This is especially true if you have to bend the cables near the connectors, for example behind a wall mounted flat-panel TV. I've bought three or four in the last 12 to 18 months as I tinkered with the living room setup. They always seem to fail, not in use, but when I've been fiddling.
I echo the point that the 1's and 0's coming down the wires probably don't give two hoots what kind, or price, of cable they're whizzing along, but when you get to the connections at the ends, that's where the problems occur.
Buy your cables by the quality of the connectors. Period.