Girantina V lost abyss

Hey all. I was just wondering if someone could point me in the right direction. I’ve been collecting cards for only a Hangul of months and don’t really know the ins and outs, a grail card of mine that I’m trying to currently buy is the Girantina V lost abyss. The card is worth roughly £1000 plus in a grade 10, however I’ve found a handful of them going for a fair bit cheaper, these cards in particularly being Korean. Does the card being Korean therefore make the card less valuable? Is this a replica? I’m just wondering as this deal sounds fair too good to be true, so I thought I’d reach out and get some peoples opinion.