Every Inventory Management System should have this option:
allow the user to input a Supplier Ratio value which will calculate appropriate quantities and costs for inventory that is purchased or sold in differing quantities.

For example:

I just placed an order for a product that comes in a 10 pack. We sell them individually. Each time I order this item, I must recalculate the numbers for what my individual cost per item is, and also adjust my quantity appropriately.

If, instead, I had a Supplier Ratio value, I could input into a PO that I purchased 1 (pack) at its cost. Then, when I receive that item, it would automatically add 10 sellable items to my stock at their appropriate, individual costs.

It's a common practice that most POS systems I’ve evaluated utilize, and every other system really should. As a Data Conversion Specialist for one of the larger hardware and pharmacy store Inventory Management and CRM systems, I had the pleasure(?) of delving into a number of other systems to see how they would (or wouldn't!) work. This is definitely a quality of life upgrade that I’m sure more than just myself would appreciate Dev evaluating and implementing.