I'm just the opposite. When it comes to freezing and sometimes life threatening temperatures, cost becomes less of an issue. In the summer, one could presumably ride naked and be ok.

I wear cycling specific stuff in the summer and winter but agree that you don't have to have ALL cycling specific stuff for winter or summer. But it sure does work better than non specific stuff. A jacket is a good example. It is very nice to have pit zips and long arms with a long tailored back. Everything stays covered, even when seated on the bike. The pit zips are great thermostats allowing one to heat up or cool down quickly.

My non cycling specific winter stuff:

Wolverine insulated hiking boots: I wear these when it's too cold for the Lake Winter boots. That temp is right around 20 F for me.


Gloves

All my winter gloves come from Target or Walmart.

Socks

My heavy wool socks all came from Walmart

Ear bands: Walmart again.

Everything else is pretty much cycling specific.