@DarkestKale I'd like someone to spin up a mothballed factory like's been happening with cassette tapes, but that's realistically never going to happen, for very good reasons.
@HauntedOwlbear I picked up a sealed box (of 10? 20? Honestly not sure) at the thrift store for a whopping $3 a few months ago.
Not sure if there's a thrift around you, or how many you need/how regularly you need them, but it's definitely worth checking.
Oh, and thrifting pro tip! If you don't see a particular kind of item, tell the managers or sorters/pricers that you're looking for them. Chances are decent they're just throwing them away because they think no one wants them.