A purchasing unit of measure is only used in purchase orders and do not offer the ability to sell them. No pricing will need to be maintained for purchasing units of measure while in contrast alternate units of measure do require selling prices if they are to be sold. If no sales will be occurring then purchasing unit of measure is the way to go. This can be found in the inventory item properties under the Purchasing and Stocking tab. There is a small section here showing Purchasing Unit of Measure. The setup is essentially the same as Alternate Unit of Measure except no prices are needed. Once setup it will be available for use at Purchase Order entry screen.