Depends on how often you ride, for how long, where you live, and how cold is cold.

Answer those questions and you'll get a better answer to your question.

I ride at least five days a week, for at least a half-hour each way, in Upstate NY, and is was 6°F (-14°C) coming home from work last night.

Shoe covers are a cruel joke for those conditions. Only my Lakes keep me going to work all winter long. They're now in their fifth season, so spread over five years, the original price of $289 is beginning to close in on the price of shoecovers. But I also own those too for the 'tween seasons. The Lakes are too warm for over freezing.