What do you think of buying or selling World of Warcraft gold? Is it immoral?  

Personally I don't think there is anything wrong with it. WoW is like anything else in life, if someone is willing to pay for it, then it has value. Take a look at any online game, and you will find that there is usually a market for these things.
I say you paid for your account, someone is willing to pay you for your time, why not. It's no different than paying for anything else out there.

While it's true that buying gold unbalances the player economy, I believe that everyone can and will make their own decisions. If they want to buy gold, they can do it, however it defeats the purpose of getting the money yourself. In the game, you generally get money from killing monsters, completing quests, selling items to vendors, or selling items in the Auction House.

If you buy gold, then you wouldn't need to kill anymore monsters (unless you want to) since you would have enough money to buy anything. If everyone bought gold, there would be no point to the auction house since people would have enough money that no one would have to kill monsters (unless they wanted to), but then they wouldn't be able to get good equipment (as in items that add a stat bonus to your characters stats or an effect like causing the enemy to bleed for 300 over 10 secs) since everyone has an insane amount of money, there would be no killing of monsters, so that in return forces people to kill monsters for items and equipment since the store vendors have what I like to call crap items (a sword with no stats just upgraded damage or attack rate).

i think it is absolutly ludicris to be spending damn near a 100 bucks for gold in a fantasy world.
i work hard in my game to earn gold. i spend money to get mats then create some items then sell them that is the way things are sussposed to be

Selling real gold for money is good, only if you make over 15.99$ a month, at least you get paid for playing LOL. But I wouldn't pay for WoW gold ever

I think that buying gold defeats part of the purpose of the game. There is an internal economy for a reason. I also don't hire power levelers for the same reason. Personally, and I say this as not a powergamer, I would be utterly lost and incompetent at playing any high level character without learning the abilities along the way. I have a 70 mage I am very pleased with, but I tried to play a friends 60 Druid once and got nothing but spanked.