E-Bay or your local game store are the best options. 3ds pokemon games are nowhere near as rare or expensive as the DS or GBA ones. Keep looking and you should find it.

If you live in Ireland or the UK then check Cex

the best advice i'd give is to look locally. places like fb marketplace and flea markets are ripe with cheap finds. there's a lot of junk but some hidden gems can be found in the right places!

For me i found ebay works the best especially since the gen 6/7 pokemon games have not seen the huge price increase that older series games have had. bonus points if you can get an out or regon copy since they are cheaper and you can change the language to what you speak.

I found my UM copy at gamestop, albeit for 12 bucks extra... worth every penny though.

You got to seek very well in local stores, online like ebay, and any other sources possible. Gladly the 3DS titles are not in the horrible price gauge of thee GB/GBC, GBA and specially DS titles (Payed $60 for a copy of OG Red in NYC Book-Off and it was dead on arribal :3).

prolly somethin like an old games store, there's one near me called Old Skool video games & more

Thanks all, I'll try my hardest to search for some games!