I can't claim the credit for this post. The idea came from this pin (see more of my school based Pintrest board here).
I bought my plastic containers from my local Countdown, and I think it was around $3 for five. I also discovered that margarine containers fit borders too (just), however they are not clear and make it harder to see what is inside.
If you are going to go to the expense and bother of using borders in your classroom, then I thoroughly recommend spending a little extra and protecting them while in storage.
Some might say it is a little over the top in organisation. I say its a beautiful thing.