Don't forget the option of getting a used set of winter wheels/tires. Keep your eyes on the classified ads on this forum, Craigslist, and so on.
I got my used set of 16" WRX wheels (they could use a paint job) with Blizzaks (tires only have 5k miles on them) for $280. No TPMS. But my traction will be secure, and my original 17" wheels won't take the winter abuse.
For that price, it was a no-brainer.