Well as Andy says the original first MOTU figures came on 8 back cards which fetch high prices, afterwards the where released again with 12 characters on the back and a yellow starburst added to the front which read "The original". I had a super minty HE-Man like that which i sold for about 600£.
Now i know with MOTU foreign variants are not that wanted with MOTU collectors as the original regular 8 backs.
Wich SW, if you have a Kenner 12 back or Canadian 12 back in similar condition the Canadian will fetch more money, with Motu its sadly the other way.
But its an very nice skeletor anyway and you have a clear nice looking bubble, so i guess you'll be spending a few hundred to get this one.