Or Lunchboxes that guarantee to give you something you don't already have.
Make it cost 500,000 caps or $1.99 or something. I don't think my explorers are ever going to get the last 3 weapons I don't have in my main vault.
Or let us build Mojave Express boxes and transfer items (or dwellers!) from other vaults.
My OCD is killing me having 3 blanks in there.
Help.