http://www.walmart.com/ip/Haier-3.5-...-White/5751095
Takes up a small area and you don't have to keep it with the food.
Frozen rat pups here are $0.25ish but what's expensive is the shipping. If I lived to where I could drive and pick them up then it would be like $0.55-60 cents. The shipping is generally $40-50 because of the cost of dry ice and shipping with the weight of frozen stuff.