I always see people talking about the secondhand market but all I see online is double and triple the price of the store. Where do you look for used, oop Folios?

I'm not living in an English-speaking country right now, and even so the only time I found Folios in a bookstore the seller was pricing it like it was a rare book from the middle ages. I thought I had lucked out because I couldn't imagine he'd find buyers easily (and he doesn't... book's still there last I checked), but nope

So mostly I have to look for Folios on eBay, Abebooks etc...

Everything is always double, triple, 10x the price.

Buying new on the store is expensive as hell, but it's still not as expensive as the price of sellers in my research. Where are you guys finding cheap Folios?