I asked a guldie who buys a lot of stuff and said 1000:1 is a general rule of thumb. It fluctuates depending on supply/demand obviously, but from what I could tell (checked different items on a couple of servers) from my simple math, things seemed to range in the 800-1200 area. So that sounds about right.
I saw a couple of account artifacts on Harbinger for 700k. I would've bought one for you but I'm flat broke. I've been wasting money on crafting materials to max out my recipe books. But if you want me to, I can gold farm and probably have it by Tuesday.