Yeah, doing 8 classes to 15 in rapid succession is probly something in the neighborhood of a 5 hour time dump all told. When i took the plunge i did one city per night, so it was only 2 or 3 classes per sitting. One way to space out the 5 level plan is to shoot for 1 class per session. So today might be a goal of 5 levels on weaver, next time try those same 5 on alchemist, and on down the line. And dont underestimate the gains you can get through those grand company supply and provisioning missions. You can always buy the item(either from a vendor or the market board) if you dont have time or the mats to make it yourself, and starred recipes are always worth taking a shot on. If it hypothetically takes 2 weeks worth of sessions to get each class 5 levels, but you get a handful of "free" levels along the way its just less work later.