I wear a Marmot shell I got for $70, not as nice as the Helly Hansen that I ripped in a crash, but gets the job done. I've had more expensive cycling jackets and the only benefit to me was that the arms flap less in the wind. Not worth the extra dough to me.

Nashbar polypro tights for below 40° is the only bit of cycle-specific gear I wear for commutes and only a few days a year.