Why not enable the feature to change your name once but for free? Charging 9.99$ won't really solve the problem since not everyone of us is willing to pay this amount of $. I would be a steal from Microsoft...
It would be more feasible for Microsoft to at least be more flexible with name changes, maybe a maximum limit of 3 name changes per account? This is all just speculation for now, we'll wait and see.
I personally believe it should be like Steam name changes, every account is linked to an ID and that ID = what you are banned by on the server if you get banned, but you can change your name infinitely at any time for 0.00$ This would allow for roleplaying and such between different servers.
It would be cool! but if i change my username from UglyPro2123 to something like ProMaster2123 and then someone knows that my username has been changed they can change there name to my old name and maybe one day i would like to change it back but i cant OR maybe when i join a faction and then i change my username the members may not know its me or when i do /f who ( shows the members in the faction ) it might say UglyPro2123 instead of ProMaster2123. But i would LOVE to have it!