Sportsmans Guide has them too for $6. I picked up some food grade buckets from Dunkin Donuts. They get their icing in them and typically toss them in the trash. They have some smaller sizes, compared to the FYI store paint buckets.

A "bucket" strategy could be to purchase one gamma seal and store items that may need replacing over time. The screw off lid allows for relatively easy access to replenish. The rest of the bucket would have the default snap on lids. Then place one of the claw lid remover tools (available in most paint stores, I bought mine at Ace Hardware).

Then in an emergency, you'd open the gamma seal bucket, get the claw and open the others as needed. I'd also add a lanyard of some type to the claw if you have a lot of buckets.