A price can be found only if the order unit is the same as the pricing scale unit (entered here). The order unit is determined by the order code and is almost always 'Purchase unit'. Purchases are made in stock units only if the order code is 'Purchase to order, custom'.

This means that if you have a pricing scale based on purchase units, the pricing scale will not be found if you are making a custom purchase. To avoid this problem, you can enter the pricing scale twice, once for purchase units, and once for stock units.

When a purchase order is placed of which the delivery condition is different from the delivery condition specified in the pricing scale, the pricing scale cannot be found; the delivery condition of the pricing scale must match that of the purchase order.

To prevent a pricing scale from not being found because the delivery conditions do not match, you could specify a pricing scale for every delivery condition. It is a lot easier, however, to leave the delivery condition field empty. If you leave it empty, the pricing scale will apply to all delivery conditions. Please note that this solution only works if the delivery condition does not affect the price.