That was just an example not what we actually have to achieve. When I ran the Lambda group buy over 300 keys were purchased, everyone that ordered got 2-5 with only a few getting one key, and a few getting 6+. Adding the keys a-la-cart will make the ones that are part of the base set cheaper and help cover the new legend fees.
I think with Cherry legends, a custom color that has never been done before we, an a good selection of cool a-la-cart keys I don't think we'll have any trouble hitting good quantities, probably breaking 100 base sets.