If enough people send bad feedback on your GT then M$ will force you to change your name and it's free..
At first, I thought this was cheating the system, and morally suspect. But, I have changed my mind. The system forcing a name change when you have complaints about your name is there to prevent improper names. The OP has an improper name (to use with his students) and wants it changed. I do not think whether the name's owner wants it changed should have anything to do with it being changed for free (due to inappropriateness). Since the name would be changed to an acceptable one, a second free re-naming would not occur. The $10 fee is to prevent people from hopping names constantly (and db costs associated with maintaining all that history in every game you play, support investigating people after a name change, etc.).