Where can I get championship Riven and Shyvana?

Why spend so much? They are just virtual skins... Like I get buying skin s normally but that is a ton of money for just two skins...

Why can't they let us earn them for reaching gold in another championship? Like if we get gold we can pick any championship skin but only one?

Please help me get those skins, ill pay max 250$ or 300$ if really neccesarry

Sadly you cannot get them via codes anymore since there is a time limit now because of the whole selling skin codes! about the only thing you could get is Championship Shyvanna and only through mystery gift! Riven sadly wont be out since Riot considered it Limited Edition but they have said on the forum that possible in 2016 theyll resell it,