How many hours it takes?

From experience, anywhere from 6-10 hours total (but this is with common, tradeable equips. It'll probably take a little bit longer if you don't happen to have any common tradeable equips to use). It really depends on your classes mobbing ability and its innate strength.

I like to save the 1.5x EXP Coupon from Tot's for 80-120, if I'm doing Link Skill mules.