Personally I can't understand why anybody would spend money on something that they can legitimately collect just by playing the game. Pick up enough Gems in Temple Run 2 and you can resurrect yourself. Being able to 'buy' a high score via in-app purchases just doesn't seem right, but as there are people with scores of 100,000,000 on the Temple Run 2 Game Center Leaderboard, some people must be doing it.
Anyone that knows how to edit the game files can have any high score they want in game center, i myself don't use game center, i just play when i'm bored, but i got mega coins & gems ... lol