You can visit @kpopdowntown on Instagram. It is a Malaysia based shop. There is a special batch for young forever if i'm not mistaken. I've been buying albums from that shop for two years already. A really trusted seller and every album you buy from this shop will be counted in charts.

kpopmart is legit. I got most of my albums there. And the young forever album is on special right now, so get it while it's still cheaper than the original price :)
Here's the link: http://kpopmart.com/product.php?id_product=10104&ps_full_site=1