This has long puzzled us and the solution is very simple. Like the hotdog, hotdog bun packaging conundrum, customers buy a four tooth milling cutter and have to buy inserts in packs of ten. That leads to a lot of boxes of two inserts floating around.
We have seen some vending machines where the supplier bought empty insert boxes from companies like Rose Plastics. Then they put ONE insert in each. This works okay for turning, but not so well for milling. The end user must request and dispense a multiple number of boxes to match the pitch of their milling cutter. It has consumes valuable real estate in the vending machine. We have a better solution.
Package inserts in the same quantities as the number of milling cutter teeth. Best practice is to regularly change inserts screws, so this will encourage changing them after each inserts change (in this case four cutting edge indexes). Depending on your inventory control system, this may require some extra work, but you can always assign new part numbers by adding a dash quantity to the SKU (e.g. 999999-4). If you have an available insert pocket add a dab of Never-Seize compound. The tiny tubes supplied by manufacturers are difficult to you and often get lost. You can buy a large tube or cartridge from a hardware store and it will do a lot of boxes. If your customer doesn't use the compound and doesn't change insert screws often enough they risk not being able to remove the inserts and having to toss the cutter. You are doing them a big favor with this kind of packaging. You can make an additional profit by selling the screws with each box. You can buy them from your insert supplier or from a specialty hardware manufacturer like Maple. Admittedly, you will have to configure boxes for different sizes and pitches of milling cutters, but you will delight your customers with the convenience.