Originally Posted by
JRule
Your numbers are correct, but you're looking at them the wrong way. Your scenario that you used proves Freyalise right.
Let's take a closer look at your math -
Level A = 3 hours normally, using the buff turns the level length into 2 hours. Thus, saving you 1 hour, or 30 minutes PER 1 hour of the buff.
(1 hour saved/2 buffs used = 30 mins per buff)
Level B = 5 hours normally, using the buff turns the level length into 3 hours and 20 minutes. Thus, saving you 1 hour and 40 minutes, or 30 minutes PER 1 hour of the buff.
(1 hour 40 minutes saved / 3 hours 20 minutes buffs used = 30 minutes per buff)
So again, it's all relative. Use the buff when you think you'll be doing the quests as fast as you can, and not having downtime.
The math works out always to be 30 minutes per application of the buff. Think of the buff as a 50% time saver instead of a 50% exp increase.
See: Level C = 12 hours normally, using the buff turns the level length into 8 hours. Thus, saving you 4 hours, or 30 minutes PER 1 hour of the buff.
(4 hours saved / 8 hours buffs used = 30 minutes per buff)