Way back in the 90s and early aughts, Toys R Us used VAX terminals (and then, emulators on PCs) to do a lot in a local store.

Inventory of other locations, and the individual details of a stocked item were one of the functions. This additionally displayed the markup/profit percentage for a given item. I understand that these numbers may not have been completely accurate, but will be sufficient for demo purposes.

Most toys, movies, and video game titles claimed a ~20-30% margin. Private label clothes and such, slightly higher. Game consoles showed ~1-2%. When employee discounts were finally adopted, it maxed at 10%, and thusly items like game consoles were excluded.