How do I connect my MacBook Pro 15" (2011) to an HDTV?
You may want to check out Monoprice. They have a ton of adapters, cables and other accessories, which in my experience have all been of good quality, for much cheaper prices.

They have the specific MiniDisplayport or Thunderbolt to HDMI Adapter you need for under $7. They've got a pretty extensive collection of cheap HDMI cables to go along with it as well.