Retail Price has to be found, that is the most specific price in the Store in question after all valid Promotions have been calculated.
Next it is checked whether there is a Periodic Offer that applies in this case. If that is the case it is calculated for the Retail Price that has been found.
If the sale is connected to a customer that should get a special price then this price or discount is found and compared to the Retail Price already found. The customer will get the better price of these two.
An exception to the previous points is if there is a Deal available, since it overwrites all the other offers.
The price obtained here is the basis for the offer calculations for instance the Line Discount Offers and Total Discount Offers.