you can buy mirror tiles from any home-improvement store like Home Depot or Lowes for $1-2 US for a 30cm x 30cm tile. You'll need to buy a special glass-cutting knife if you want to cut it, it's very hard to use!!! My dad had a lot of trouble but in the end it looks pretty good
I suggest try finding a glass store around your area to do the cutting for you, look in the yellow pages