I picked up two of the orange buckets with gasketed lids from the local Home Despot. I split the sack between them so it was 25# in each bucket. Might be able to get another couple pounds in each one but don't need to right now.
I blame Snookie. Only because she should be blamed for everything.
I use the rubbermaid roughneck tubs to store grains in. They're not airtight, but I go through grain fast enough that things seem fine. I can't see spending more on containers at this point in my life.