You are misunderstanding the concept of marginal unit costs if you disagree on that basis. AAA software is wildly expensive, but each incremental copy sold is

You are misunderstanding the concept of marginal unit costs if you disagree on that basis. AAA software is wildly expensive, but each incremental copy sold is not wildly expensive. With a tea kettle, each incremental copy still costs you metal, heating elements and plugs, so the unit margins are smaller.