For myself, getting any checklists or hobby recognized variations as part of my set is a necessity. For 1956 that meant just 2, but for 1957 that meant 8 checklists since there is a Blony and Bazooka version of both.
And then there are the 4 Contest cards, the Lucky Penny Insert and the Lucky Penny charm itself....and an unopened pack or two, paper proofs, salesman sample