Trilarion: Probably some kind of DRM (in the galaxy client) could help enforcing regional restrictions.
I doubt that, that's the one step they can't make. Something like what theyr'e doing with the Witcher 3 where you simply can't gift it at all if you're in lower priced regions, or other/more purchase restrictions seems more likely.
Only allowing payment options from the region in question, only allowing the same payment option to be used on x accounts, restricting purchases (even gifts) to X per account total, allowing gifts in those regions but not allow them to be activated if you're not in that region. Stuff like that is more likely I imagine, though none of them are optimal.