Choi Problem mostly relies on simply farming the zeny for said items. In the time spent you could buy around 7-8 weapons from people that had leftovers of them by doing the instance daily and selling for drops.
I like that costumes are tied to a more RNG/difficult way to obtain, but borderline annoying doesn't fit in the bucket. None's fault of course, thus I present the alternatives for a more feasible and reasonable farming method.
Also to add on top, the frustration of locking dialogues makes the experience even worse, in my honest opinion.
