A quick review for the newer readers. I hit Professional Grand Master Inscription on 6-28-09. That was the point I took inscription seriously on the Auction House (I started working other markets shortly after that). That was about 10 weeks ago. The progress I made was huge. I would like to thank Greedy Goblin and Just My Two Copper Forums for showing me this market.
Today I had 95,000g in the guild vault. I tend to keep most my gold there. My main holds on to 12k gold in case I am ever in a raid and want to purchase a drop. There is about 6-7k gold combined on the other characters. They are each dedicated to different markets so have the gold to buy the stuff they usually buy in bulk.
I would love to count some of the gold I spent in my total but that would be cheating. I dropped 60k gold on the ToC crafted robe and bracers when I was told nobody could get them. I handed 20k as a gift to some friends and I sent 5k to my inactive 2nd account to keep it safe. That's 85k gold missing from my total.
So after 10 weeks of mostly inscription and a few other markets I have 113,500g to put me at 11.35k gold a week in savings. If I was to include the splurging of gold that number would be 198,500g (19.85G weekly income). If only I would have held onto that gold, I would have hit the gold cap in the next 2 weeks (3 months total).
I know I need to move from camping the AH to just undercutting it for 2 days but I look at that income and hate to mess with something that is working so well. I would bet that I would make more gold because I would spend just as much time. The big difference is how many more markets I could work. I have some very profitable ones just collecting mats because my scribe spends all his time milling/inking/glyphing.