Someone linked a poster over on reddit, and it seemed surprisingly cheap. Here's a link...
https://gamecaseking.com/products/golde ... a398da858d
BUT! Just be warned, there exists the potential that this might be a scam. The guy on reddit ordered one, and we'll see what he reports back later... but as it stands, the price seems a surprisingly low for a poster. I mean, I just bought several .hack and Monster Hunter World posters and they were like 10 bucks each.
https://www.reddit.com/r/GoldenSun/comm ... h=169d5d62
This is the reddit thread, so if you're a bit gun shy on this like me, keep an eye on it for when the guy gets it in. Who knows, maybe it really is a pretty good deal.