Very interesting - thanks. I suppose the other worry is that if you underestimate the cost of the triple then you might underprice it. A popular style that's underpriced would sell well, but not make you much (or any) money. That could ruin the business.
It used to be everything manufactured needed a lot of labor/machine hours, so it made sense to allocate your factory overhead to units based on how many hours you spent making it.
What you're describing is exactly what happened to the big auto makers. Some of the components they made in-house looked like they were profitable under their old cost-accounting system. When the auto makers switched to activity-based costing, they realized those units were more than 30x more expensive to make in-house versus subcontracting them.
Basically, they had a few really profitable lines, and a lot of unprofitable lines, but their costing system couldn't tell which were which.
Around 2009 the Financial Accounting Standards Board introduced a requirement that you need to treat excess unused capacity as a period expense, instead of a per-unit expense (cost of goods sold). The automakers would have been able to avoid bankruptcy if they had had a clear idea of how much their products actually cost to make. Investors would have been able to make better decisions, as well, if they knew how expensive it was to have so many factories sitting idle.
Having worked in the auto industry for over 30 years, I can't agree with most of what you said. The reality was complex, and it was more than accounting that was the cause.