I bought winter shoes (Sidis & Lakes--got the latter at a really good price) last year and don't regret it. Layering w/my Ruby Slippers--even with insulated shoe covers, wool socks, chemical toe warmers--didn't cut it for me. Using the winter shoes made it bearable to ride outside on the coldest days. I still had to layer w/wool socks and use chemical warmers, though. I anticipate using both pairs of winter shoe/boots for many, many years. Therefore, they are a solid investment, especially since I hope to commute by bike all winter long (means riding after dark, when it's coldest).

You might be able to find the Lakes on sale at Performance or Nashbar. SheFly recommended them and they worked out great. They were much less expensive than the Sidis. I do prefer the Sidis for the most part, but the Lakes seem to keep my feet warmer when its below 25 degrees. I call the Lakes my Herman Munster boots--for good reason!! LOL