Sorry to bring up an old post, but if you're still looking, try your local Petsmart/Petco. I know that is normally considered taboo, bit it may surprise you.
My wife and I stopped by a Petsmart (we had to pick up some hamster food) and I had to go look at the fish (ok so I'm obsessed) and I noticed a tank FULL of MTS. There had to have been 100 of them from 1/4 inch to a full inch. I asked how much they sold for and the gal looked at me like I was crazy. She told me I could have every one in the store, even begged me to take them. LOL! So who knows, may be a way to go.