Apple is extremely useless when to comes to pricing products across the globe. I have noticed it across other things as well. They are not good at currency conversion it looks like or they are and they just like to charge more in the areas where they get the most sales.
My experience of this (try not to judge too much) is when PokemonGo first came out in Australia before the UK so we all made AU apple accounts to download the game, the in-game currency cost less when I used my AU apple account then when I finally got it on my UK account. Apple sucks but daym do they make nice looking shit.