It's well worth the money. I've had it for a couple of weeks and haven't flown a second without it. All you need to buy is this: http://www.naturalpoint.com/trackir/02-products/product-TrackIR-4-PRO.html

You don't need the TrackClip Pro.

As said earlier, make sure there isn't any sunlight in the room you're using it in (there can be light.. just not like streaks of sun on the wall or whatever.. Not sure how to explain it.. lol)