To me it comes down to layering (like thenomad mentioned). It is difficult to regulate temperatures when their could be a 20 degree swing between when you leave and when you come back. Then on top of that you want it to handle extremes in weather.

I am a year round commuter. I really don't have anything cycling specific. A base layer close to the skin works with regulating temperatures. On top of that I have different shells that work with weather changes. Most of my clothing comes from discount stores and were acquired over time. They are not hi-viz or reflective. I have different things for that. Everything can be packed away and not take up much room.