I'm still holding out for his first keychain or strap. I'd definitely order a box and stalk auctions for it no matter how long it took to surface. Rakuten is good for gachapon straps that don't appear as boxes on other stores, but I might get cursed by best boy syndrome and he'll be sold out or far too expensive compared to the rest.
I've been keeping myself in check by going one item per artwork since there's a lot of repurposing, and don't buy the ones you never liked anyway just because the not for sale poster is rare as fuck and you haven't seen it in those colours before. I already have a ton of duplicates so it's going well.
Matsufags must have it tough, I've seen at least three wedding suit looking keyrings in a row and stuff for every season. I guess they can pick one or two then wait for sales but I'd never trust the ones I sort of want to not sell out first.