A random google shows that it's highly sector dependent, but it's probably closer to 20%.
Having worked in consumer electronics, and knowing rough BOM cost of products that we made in the millions, I can say (at least for the companies I worked for), that there wasn't anywhere close to a 300% multiplier, even going from BOM cost to MSRP. Even extreme outliers like Apple (who supposedly have a raw BOM cost of $475 on an MSRP of $1099 for the 14 Pro Max) don't get to 300%. That markup goes directly to Apple; As a retailer, you might be making 10%.
That reflects the lost income potential from the shoplifting. Not just how much money it took to physically build an individual unit (and package and ship and stock it etc).
Now if they never sell at MSRP, then probably a slight discount from MSRP when reporting is fair. But definitely not just the BOM cost or similar…
Eg an Apple laptop has a cost to build (cost being money, materials, time). If Apple sold that laptop at $2k, I don’t think they would value the loss at six figures. Given how little Apple discounts things, they probably value the loss (fairly) around the MSRP or ~10% or that.
The accounting approach is driven by taxation, and governments strong preference for maximising their tax take.