on the cheap, you can use any fleece jacket for a mid layer (although, the thicker, the more insulation). I do suggest you get one with pit zips, as they come in extremely handy if things get warm. I'm using a fleece under my thin shell outerlayer and this combo has surprised me with how warm it's kept me through some pretty cold/windy storm conditions.
(btw, I tried the Under Armor Coldgear compression wear and didn't like it. It was too tight and the inner material relatively raspy. If that's all you got, then fine, but there's looser, more sheer fabric, and more comfortable underlayers available at most stores that are cheaper than UA and just as moisture wicking and warm.)
Last edited by extra0; 03-01-2013 at 01:58 PM.