Hi Shams,
You can achive this using a pricing requirement to be assigned for the pricing condition type in pricing procedure (V/08) and cannot be achieved by incompletion.
Create a ztable capturing the saes org, distribution channel and division fields.
Develop a logic for the pricing requirement as follows. If the sales area of the sales order is what is present in the Ztable evaluate the condition type else neglect the condition type.
Now assign this pricing routine reqirement in pricing procedure for the condition type.
Hope this explains.