DH loves underarmour, much to our checkbooks dismay, LOL. The cold weather gear is totally worth it, though. It's a lot more durable than the equally expensive silk longjohns and is so warm. He got me a pair of the wintergear longjohns and longsleeve tee at the outlet in MD last spring and I love them!
Yep, they're expensive, but we both feel it's worth it. His job (cop) often requires him to be outside for long periods of time in both hot and cold weather... and the hot/cold gear work the way they say they're supposed to.
He'll probably go back to the outlet when he's in DC next May. It's the way to go if you've got one near you.