Storage cost is another important factor. Here is a concrete example of how
removable media may lower the overall storage cost. Suppose that a hard disk
that holds X GB has a price of $200; of this amount, $190 is for the
motor, and controller, and $10 is for the magnetic platters. The storage cost
for this disk is $200/ X per gigabyte. Now, suppose that we can manufacture
the platters in a removable cartridge. For one drive and 10 cartridges, the total
price is $190 + $100, and the capacity is 10X GB, so the storage cost is $29/ X per
gigabyte. Even if it is a little more expensive to make a removable cartridge,