In WoW the gold has been non-issue since.. at least an year ago. The only situation where it matters any more is when you buy BOE epics or extremely rare drops from AH (which have highly inflated prices due to the ease of obtaining gold). And with these, the more you buy gold, the higher these prices inflate to - and they are all luxury items for scrubs that don't have the necessary social skills to raid. All gear that you actually want to wear, assuming you have a choice, is Bind on Pickup anyway - you have to kill the boss to loot the item, can't just buy it.
As for all other use of gold in WoW - item repairs, consumables, crafting... it is insignificant compared to the amount you get from just playing the game. There is NO NEED to farm gold in WoW any more. Period. Only players in my large WoW guild who are commonly broke are the PvP idiots who do nothing but arena all day long - unsurprisingly that doesn't reward them with gold while they keep spending gold to enchant and gem their shiny PvP epics. So you have to go do some PvE from time to time to fund your PvP activities? Oh. My. God.
As for the leveling... it's a major piece of the content of the game. Sure, people gripe that their alt number four or five is a pain to level as you have already done all the content a couple of times, but do you really need that alt number four or five? And if you think you do, why do you think you are entitled to cheat (by using a powerleveling service)?