It appears I cannot comment on replies due to low karma, so I guess I will comment in a new answer.

@lars Aam
I do not see a way to define package pricing. In Inventory -> Configuration -> Product Packaging, creating a package allows you to name the package, assign a product, define contained quantity, its barcode, and via checkmark boxes, select whether the packaging is available in Sales or Purchase. 

I also do not see packaging as an option that can be chosen on the web store.

@Diiconnect Innovations
Interesting suggestion on kits. I looked at it. In this scenario, I would create a product named "Case of Cups" or "Sleeve of Cups". The main problem of this, it appears, is that you have to define the pricing of the kit.

Prices fluctuate very wildly and frequently in our industry. Our markup is setup as cost + 50%, and so we have to define our base unit as the unit in which we purchase. (Otherwise we would have to divide our $74.18 purchase cost of a case of cups by 1,000 routinely to update pricing.) And again in this scenario, we would have to update pricing in the base product and the kit unit.

I do understand we may need to change our processes to adapt to the capabilities of the software.

You get problems whem you use unit of measure like that.  I know odoo many times recommended such a way to use unit of measure.  This is a typical example where it make lot of problems.  Set it up the easy way, as it is.

Base unit = 1 cup.

Package 1 sleeve = 40 cups.

Pacake 1 case = 25 sleeves. 

This is standard functionality, and you need no development.  Can be selected on the web shop, sales order.  You define prices pr package.

Try using kits.

• Install MRP (Manufacturing) app
• Select Bill of Materials from Products menu
• Select Kit under BoM Type
• Create your kit product (make sure to set as consumable)
• Add your item as a component to the kit in the appropriate quantity