I think your post is great and it's not irrelevant. I'd add two things.

The first is I think everyone would agree stern pays at least half of what us as individuals can buy parts at a retailer for. So if someone put together a list of all the parts needed for a typical stern and it came to $6000 for example, sterns cost is at least half that for parts alone.

The second is consider what stern games used to cost in the late 2000's. They made enough to stay in business then, so you know a large portion of the increase since then is profit