Yes it does. During the purchase, if the said inventory item has never been purchased before, arrives with its base unit. If we change its unit during the purchase, then it will arrive as the changed unit when we re-purchase it.
Example: If we bought the unit as "parcel package 20" from seller A and bought the unit as "parcel package 24" from seller B, during the purchase from seller A, it arrives as 20 units and during the purchase from seller B it arrives as 24 units.
