What is the cost per chip to store?
So once you have figured out how much space will your collection will occupy. The related question is how much will it cost you. You figured out how many chips you will collect and you calculated the unit-storage-space, now you need to calculate the unit-storage-cost. In the unit-storage-space calculation you selected a standard box size. To determine the unit-storage-cost take the costs of the box, add the costs of any other storage/packing materials (like bags, tags, foam, etc.) and divide by the number of chips that will fit in the standard box. You now have your unit-storage-cost.
What is does it cost to house your collection?
Once you have your unit-storage-cost you take your total number chips and multiply. Also, the considerations for growth space reservation needed to be added. Assuming your are storing this in your house/apartment, which you will initially do, you are done, but if you rent climate controlled storage space, or build an addition to your home, you need to factor that in as well.If you have that large of a collection, you should consider security and fire control systems as well.
What is the incremental cost to add a chip once current storage is filled?
This is just your unit-storage-cost until your box is full, then you have the costs of the box to consider, even for one chip. This may be a small bump or a big cost bump depending on the box cost.