Diagnosis
The Customizing settings (IMG) for pricing element 01 (list price)define that this pricing element is identified in the pricing procedureusing a condition subtotal. The list price should refer to the subtotalwith subtotal field 9. You make this setting in the following activity:Identify Predefined Pricing Elements in Pricing.
You therefore cannot use this pricing element for simplified pricemaintenance in sales documents.

System Response

Procedure
You can only use the pricing element 01 (list price) for simplifiedprice maintenance in sales documents with a different configurationoption.