People really got to stop using BOM or Bill Of Material for the actual final price of product. Have to factor in shipment of the parts to be put together, labor for putting together, and cost of inspections. Using BOM to say a certain or any company is cheap is not painting the whole picture in manufacturing.
Here's a simple example the BOM for making certain parts from plastic lets say a generic material is from ABS Lustran (which is what a certain company I know of use) is roughly a few cents per pound. 1 part ways less than a pound after machine make the part. so is that part still only should be a few cents because thats what the BOM says. Factor in machine time, labor time, pressure drying material time, qaulity assurance, and many more and that BOM that was a few cents per pound is now 5 to 10 dollars and thats just for one piece. This is not factoring everything else.
Basically using BOM to gauge a price of a part to go into another part is not very good. People dont work for free, machines need power to run, quality personal dont work for free and these are the people that are no factor into the BOM. Usually if its an already made part thats need to be assemble. The cost of the parts goes up 50 to 100 pct before leaving manufacturing. At the end consumer the price goes up another 50 to 100 pct easily so that retailers and everyone in between get there cut.
It's a perfectly valid thing to use when you're comparing the drive they're already putting in vs putting in a slightly different drive. We're not talking about a bunch of additional costs by ADDING something, we're talking about something that is virtually identical and you're merely deciding to use the cheaper option. So, in situations like this, BOM is actually perfectly correct to use. You're just trying to obfuscate that to defend Sony here.
Shipments: they're already doing that.
Labor to put it together: They're already doing that.
Machine time, labor time, pressure drying material time, QA time, all of that is already factored into the 15 dollar difference since that's on the drive manufacturer not on Sony, but go ahead and pretend it's not.
The drive itself has no 'parts' cost to consider, BECAUSE THAT IS PART OF THE FIFTEEN SONY IS SPENDING. On Sony's end, as long as the drive is roughly the same size as what they're already putting in the machine (it is), there is literally no additional cost beyond the cost of the drive itself.