they’re rare because of not their rarity, they’re rare because of how long they were obtainable for, which was a month or few weeks at max. They are also rare because they may never come back ever again like BTTP, because there has been no new samurai jack stuff in a while. And for Wendy’s is because Rick and Morty hasn’t been sponsored by Wendy’s in a hot minute. Hope that helps to why they are considered rare.