How about you compare CDs/DVDs to DVDs/Blu-rays instead of cartridges. Mass producing custom cartridges with motherboards/chips vs bulk CDs is laughable. I remember buying PS1 games (before PS2 came out) for $19.99 MSRP, not on release day I know, but even back then I was a cheapass. 2-3 older proven good games, or 1 new game I don't know about.
I don't call it my backlog, I call it my video game collection.