Some strong responses here
I am addicted to WoW. I don't play every day, but maybe 4 nights out of 7 in the week I am raiding with my guild. That's nearly 20 hours or so of gameplay on one game a week. Quite a lot.
Personally, I would never buy gold or a powerlevelling service, purely for the worry associated with the transfer, credit card payment or account details. I have considered it, but then realised that if I went down that route, it would clearly signify there is nothing more for me in the game, and I should move on.
Time = money in ANY MMORPG. No matter what your action is, whether you're standing still or creating runecloth bandages, that time equals money. You are paying for it. Others in the game world will always be profiteering. This is the clear motivator which keeps millions playing - the advancement of your character beyond others. Virtual bragging rights is essentially all it is.
People like to criticise farmers, and yes they can be a nuisance to the game, but they can never be stopped. You need to realise this - no matter what attempts the game moderator's / community make, someone somewhere will always be profiteering through 'dodgy' means. I have learnt to accept famers and botters, and to try and understand what their techniques are. This in turn helps me to advance in the game at a faster rate than others.