The E12s specifically had a significant jump: Following the big recall in 2024 the new, much more reliable E12s came back packaged as 2 for $28 instead of 3 for $26.50.
The last year or two their F15 2-packs went from $30 to $33. I think all their other motors have been stable for a while now, particularly the 18mm motors.
The motors are less subject to tariffs, shipping, etc etc etc than many other products because they're made in the states. To my knowledge the black powder is sourced here as well (*). I don't know where the casings come from---I believe almost literally all raw paper in the US ultimately comes from China---but I assume Estes either have such a huge stockpile they haven't been affected too much yet, and/or the foreign sourcing is so upstream it hasn't had much impact. Motors are also efficient to ship, i.e., distributing them---you can readily pack a lot of motors by weight & dollar-value in a small space.
The foreign-produced kits though are very subject to /waves hands wildly at everything happening in the world/, spread across production, customs, and not being efficient to ship---they take up a ton of space for the weight & dollar-value.
(*) A few years ago Estes actually bought the last black powder manufacturer in the US, to my limited understanding with financial support from the DOD to keep it open. But I thought I saw something about it later being spun off and then very recently acquired by another party but I could be mistaken. I believe in general a lot of black powder in the US is imported from Switzerland. I'm sure there are people here more fluent in this whole story.