Your commute sounds very similar to mine. For several years I've been using a white strobe in the front and a red strobe in the back. They came as a Cateye package that cost $20. Each uses 2 AA batteries that I change at most twice a year.

I realize some people think they need more expensive solutions, but this cheap setup works just fine for me, and I do a lot of riding in the dark, especially in winter.