Yea, just go to the deli in those big stores where they sell cakes and such. May have to leave your name and number but a call will get you a bunch in a week. May get lids too. If they have icing in them, let the set under the drip of a roof for a couple of weeks with water in them. Then a little soap and a scrubbie, they will clean right up.
Check you home improvement centers for busted bags of crete. May get it for half price or less. Those clean buckets with lids come in handy then.