Time is money, indeed. Here is an example:
Just a few days ago I found out that reputation gained had changed and I could go back with my 60 druid and do the quests I missed out on as a youth and get full rep. So I started out on Wednesday, with about 25 gold on my druid. I did lowbie quest after lowbie quest, searching for anything I may have missed along the way. Any elite quests in Silverpine or Stonetalon, etc. Anything! I started out also at roughly 2k into Revered. By yesterday morning I hit exalted and also had made well over 100g. And that is picking up everything from every mob I killed(yep, all those little coppers do add up!) and selling absolutely nothing on the auction house. I was worried that I may not have enough money to buy the epic wolf once I hit exalted, but the money just rolled in as I did quest after quest.
Now, granted, at 60 I do get a bit more for the quest when it is a coin reward, but at the lower levels the difference didn't seem like much(I wasn't getting gold for any lowbie quests, that's for sure!)
So gaining money at any level *can* be done, easily. And money can be made just about *anywhere*!! It just takes time. =)