How much does XBOX live cost on a mobile data plan?

This may be a bit of a difficult question to determine, but does anybody know how much it would cost to use Xbox live over a mobile data plan? What I mean by that is if you used your phone as a modem and connected it to the xbox. I'm guessing it's quite expensive but I wanted to be sure.

Thanks

P.S my gamertag is James010111 if anyone wants to add me. I usually either play GTA 5 or Minecraft.

Depends on your service and your data cap

Playing online isn't that demanding on data because most of what's happening is just bring read from your disk/hard drive. The only thing that needs to be downloading is other players locations and actions. So using xbox live through a mobile isn't too bad but it does depend on how much you play, how many players there are in a game and apparently if you are the host its a little more demanding but mobile connections rarely get the host spot as more stable connections are automatically selected.

Either way I wouldnt do it unless you have an unlimited data plan, especially if you pay monthly.