Possibly the most complicated Addon I have ever used it is also one of the most powerful. You can build custom Visual and Audio warnings for virtually any situation in the Game. I have used it for Buff Stacks Low HP and Ability Cooldowns many times over the years on various Characters. Blizzard added similar Visual Warnings in Cataclysm.Git Repository: https://github.com/Geigerkind/ModifiedPowerAuras
Also note that power leveling is sometimes used to refer to paying someone else to level your character to cap as fast as possible (i.e. they power level for you); a distinction used by Blizzard is to refer to the paid leveling as "power leveling service." This behavior is against Blizzard's Terms of Service. Power leveling yourself, which this article covers, is perfectly acceptable.
Before I go ahead and settled this debate for good; I spent most hours surfing the .net to get an idea of what others were saying; if you have done the same you will probably find similar results ~ that in the general publics eyes, WoW Dugi Guide vs WoW Zygor Guides is pretty much even. U also probably found that a few opinions were biased towards the guide they owned. These findings aren’t very helpful in finding an outright winner however; they help show the fact that with what ever guide you end up choosing zygor and dugi guides, you will should be very satisfied!
If you're looking for simple, just get actionator. Set it to undercut everything you post for 1c and alt click from your bags. It will place the item on the ah window, do a scan for that item and autoset the price for how much you told to undercut (you can change it accordingly if you feel like it). It will remember if you do stacks for which items and replicate it everytime.