Performance has some good gear at reasonable prices (for bike clothes, anyway) for those temps in the middle. I like their long finger Century gloves for 30-50F, and they have several weights of tights.
Days with temps from 40 to 75 are difficult. I usually end up with a warm weather outfit (shorts and jersey), with tights anda vest or jacket over it. Roll up the tights and jacket if you get to leave work while it's still warm, and maybe switch from long to short finger gloves in the afternoon. Aggravating, because I end up with a set of work clothes AND a set of cool weather gear to haul home.