GravelMN

I know this is a zombie thread, but it is still relevant. I've found that the big box stores are selling some very usable, non-cycling specific clothing. I've purchased a couple sets of OmniWool undergarments. They are a poly-wool blend that doesn't shrink significantly as long as you dry it on a low heat setting and don't over dry (take it out just slightly damp and lay it out or hang it over a chair to finish drying). The top has a 1/4 zipper. They wick very well and are even comfortable indoors but add a significant amount of warmth to whatever else you are wearing. Long sleeve tech fabric shirts and long pants are also available in store brand at a fraction of what the big brands charge.

I've got a Champion brand tech fabric 1/4 zip pullover designed for runners. It is close fit and has a draw string hood (which can be worn under a helmet) and a pocket on the chest that is perfect for a cell phone. It is long enough to cover the back when on a road bike without bunching up in front. I've also found some running and XC ski pants that work well for cycling in the winter. Sport Hill makes a pant that is very wind and water resistant on the front and breathable/wicking in the back. They have held up well after three seasons of winter riding.

Just keep watching the thrift stores and discount racks, you can get some really good buys. As spring gets closer, you'll find more winter gear at deeper discounts. I've found that garage sales in younger affluent neighborhoods yield a lot of good sports wear, including cycling specific gear.

noglider 

I've been hearing that anything-but-cotton theme for years and never had a problem wearing cotton as my bottom layer until a few weeks ago. It was cold, and I was well dressed and warm while racing from work to a meeting. The ride was a little over an hour long. I sweated plenty, but I didn't really mind. Then when I got to my meeting, I was wet, and I got cold. So the rule is a good rule if you're going to sweat. Maybe I don't normally sweat much.