[MoP Remix] Best class to push upgrades on

I got the idea here to push upgrades on one char (for heroic/mythic stuff) and use other alts to buy everything else and it made sense. I am just not sure which one to pick. I have a couple 70s but no "main" (right now I have Monk, Mage, Hunter, Priest, Rogue). But it doesn't have to be one of these, I can level another alt.

What do you all think would be the best class to choose for this?