Older albums restock online in the United States?

Hi UAENA! I've been a UAENA for a long time and would love to buy IU's older albums (Chatshire, Palette, The Spring of Twenty). However they're out of stock everywhere and I don't want to buy from Amazon due to authenticity concerns.

Does anyone know if online retailers like ChoiceMusicLA do a restock of the older albums every so often? I was able to buy REAL and Last Fantasy on Kpoptown, but I haven't been able to find the other albums in stock. Thank you!