It depends on my workload and the number of changes I have to make to the commission. Usually between a month and two months. I usually send out updates every week or so, so you can see how your piece is progressing.
It's all about supply and demand, bro. I did $5 pieces for a long lime, until I was too busy to handle the demand. At that point, I upped the price, and demand lessened. Then, as I got better, demand increased...ect, ect. My prices are still pretty cheap, though. I'm still practicing too, man