Hmm Im not sure how your doing it if you are trying to find out a cost per item you would just divide the cost of the pack or pallet by the number of units you have. Lets say you got a $45 sample and you had 8 items in the box, that would mean your paying $5.65 for each item. If you bought a pallet for lets say $600 and you had 85 units on the pallet your cost for the items on the pallet would be $7.05 for each unit.
Example. Macys has a High end Houswares pallet that is worth $5,900 Retail
There are 89 Units on this pallet
Buyer cost is $1,273
Buyer percentage is $14.30 per unit.
Also meaning the average retail value of each item is $66.29