Originally Posted by
Arpit Mittal I think you have to buy same app twice as it goes to wp8 us not Spanish specially on computer, anyway you can try but if you came back on Spanish than all your purchased apps will be free again
I don't believe that is accurate. A while back I read something along the lines that you can buy from any region app store and it is all tied to your same live ID and you can use the app without issues. It would not make sense that if you change phone region your apps bought in other region no longer work, because, for one, people do move from country to country.
Also changing region on the phone (as well as on Win8) affect the localization of Bing News app (and probably some other region apps as well if they access info based on the set region).