I've been doing this too, though if I'm going to buy a new video game, I sub Prime's monthly option for the month, because they give you $12 off the game, and the Prime is $11 for the month.
Note of warning: You'll discover a lot of random items are now "Prime exclusive" for no reason other than spite. No special discount, they just will refuse to sell you odd and end items unless you buy Prime.
I wonder how many of those are such low-margin items that they effectively don't make a profit off them unless they restrict sales to people with prime (who are paying for the privilege)?
It's so random it's hard to tell. Like random Blu-ray discs, regular household staples like diapers or shaver blade replacements, etc. And they'll come and go from the exclusive list every couple or weeks or so, it seems. There's a huge long-running thread on Amazon's forum about it.
What amazes me, is given Jeff Bezos' general attitude towards providing excellent customer service, is that Amazon has said nothing about this practice, and it's decidedly anti-consumer. If it was just a Prime discount or something, it wouldn't bother people nearly as much, but Amazon will outright refuse to sell without Prime for a lot of these items, unless it's also being sold by a third party seller you can buy from instead.
Note of warning: You'll discover a lot of random items are now "Prime exclusive" for no reason other than spite. No special discount, they just will refuse to sell you odd and end items unless you buy Prime.