If you are looking for actual foam containers for holding eggs, specialized farm supply stores offer the best variety.
: Offers unprinted styrofoam cartons in various colors like green and aqua. Prices range from approximately $15 for small sample packs to $43 for a 50-pack. where to buy egg carton foam
(Class A fire-rated) for about depending on thickness. Where to Buy Egg Crate Mattress Toppers If you are looking for actual foam containers