Standard in foodservice distribution. The manufacturer negotiates directly with a large operator, and the distributor delivers that price, recovering the gap by bill-back.
Deviated cost is item- and operator-specific and changes frequently, so the operationally hard question is not "what is the deviation" but "what deviation was valid for that operator, on that item, on that date". Systems holding only current price cannot answer it, which makes both claim generation and dispute resolution manual.