As for the original question. I have over a million gold and I barely work at it. That's mostly from buying and breaking down ore and posting auctions before work in the morning and before bed. I let the other JC'ers fight it out for prime time sales. I get enough sales during down times to not have to camp the AH. Once a week I'll break down a couple of hundred stacks of ore and that's about it for my effort. I'm not saving for the RMAH, I'll probably spend to get my professions maxed asap in MoP then keep doing what I'm doing. I might keep an eye on the RMAH for good deals, but not gonna blow tons of gold there.
I think most of the people who play the AH act like gold sinks for Blizzard, because once they get the gold it rarely leaves their accounts.