It or the Polartec Expedition is well worth the money. It is the best stuff I found for keeping moisture off of you and heat in. Cotton gets wet when your loading and unloading gear. When you cool down, you freeze.

The Polartec is sold at Bass Pro. I would imagine that the prices of it or Under Armor are about the same. They are both expensive. Bass Pro also has their brand of the same stuff much cheaper. ..$42.00 for a set vs $140.00 for the Polartec. I haven't tried the Bass Pro brand yet to see if it works.