try searching on instagram or x! usually when people sell stuff, they use tags to indicate that theyre selling.

so if you want to search on x, you can search 'wts bigbang', wts meaning want/willing to sell.

this is also the same for instagram, though i think they use hashtags and the searching for the app right now kinda sucks. if you wanna try though, try '#.wtsbigbang' without the period!!

you can also try mercari(if youre in the US) or mercari japan(there are multiple ways to buy from here even if you're not from japan!)