No no, this isn't about roleplay. You've got gold in your pockets, but it didn't just magically end up there. You've done something to earn it (unless you've, you know, bought it -- for shame!).
In-game gold's always been easy for me, but I think it's partially because I love gathering. Yeah, you heard me. I'm the guy who has a bank character, bank, and mailbox full of ore, leather, gems, and odds and ends. Sure, I do my share of adventuring, getting dailies done while I search for blood and glory -- but you better believe that if I find someone messing with my Azshara's Veil when I'm trying to do an escort, there will be blood. I'm a farmer, plain and simple.
It wasn't always this way, though. There have been times where I offered my services for a significantly reduced fee so that people would buy from me instead of the Auction House. I'd gather loads of ore and gems, find the AH prices of them, and offer them at a much lower price than what was on the AH (but still at a profit compared to the cost of crafting). It got to the point where I didn't even need to use trade chat to get customers -- they'd PM me while I was gathering resources. My ignore list was filled with names of my AH-PVP victims who wanted to make higher profits with less effort. I was a jewelcrafter for hire.
What is your character's job? Do you make money by teaming up with lesser-skilled PVPers for Arena ratings? Maybe you lead raids for cash? Or perhaps you run a shady tavern in Elwynn Forest doing odd jobs for people?