Im considering getting these markers, but it seems like all their singles are sold out?

Just wondering if this is a common thing for all their singles to be sold out - because I'm not dropping $200+ just to never be able to get a replacement color every time a marker runs out & then have to buy a whole new set if a specific color I really love is constantly sold out. 🤔🤔🤔 If this is a common/usual occurance - do ya'll know of any dupe brands that are comparably good ?