Back to the question at hand: is the Mechromancer Pack worth $10? Right now I would say no — at least not unless you're already sick of playing as the four existing classes. And seriously, if you've played 160 hours in the past three weeks (which would be roughly seven hours per day since release), turn the PC off for a little while and go hug a human. Maybe in another few weeks, if your love of Borderlands 2 extends that far and long, then I would say yes, go ahead and relive the adventure again with a new character. Who knows? It might even go for cheap during the Steam Holiday Sale.