If you are on a budget, here's something you can do to keep your feet warm... the Scots blood in me really likes a no cost solution to a problem...

I just posted an answer in another thread which fits well here, so forgive if I copy and paste:

From this thread : Toe Covers
http://forums.teamestrogen.com/showthread.php?t=18699

You could always do what I do most of the time .... socks, plastic bags to fit over toes and most of foot but cut down so they are not sticking out the tops of your shoes, then your shoes.

Works a treat for cold days, frosty mornings, or polar blasts...
I use most often supermarket bags - a double layer if really cold day.
Bread bags are better because the plastic is thicker, but in our house it is easier to find supermarket bags.