At the end of each expedition, they all go away, but you get a partial refund.
Generally, unless you’re playing at a high difficulty level, I don’t think it’s worth stressing over decisions and min-maxing in this game (also not worth fighting the second tier of bosses, but ymmv). But, I’d strongly recommend looking at a guide suggesting which and how many items to take with you on expeditions (and also one for the curios linked above. Ed: which also has suggested provisions, so that should be all you need!). Everything else you can sort of feel out as you go.