Just before the Rising launch and when the spawn towns were being auctioned off, my balance topped out at about 19.3mil, and I spent 14mil of it on the towns themselves... ECD isn't a really good way of keeping score, though. I look at my asset list and my completed goals. That's, to me, a better measure of wealth.
Something like... $505,000 It was slightly more, but around that, then I ranked to Tycoon and was left with 5k.