http://queg.deviantart.com/journal/commission-pictures-promotion-amended-507508319

I wrote it there; figuring it out on weasyl seemed a frustrating matter. The information is not new, but the previous journal here was even older, and had to go!
In short: the range is roughly $10-40 for plain "pin-up" sorts of things, with possible discounts for characters interested in fitting the theme of this gallery (anthropomorphs that will wear shirts without pants).
I offered 20% off on other sites.... this seems to not be a popular offer! Its existence may have even put off people who ordinarily will pay full price. Next time I will offer it as a premium option and see if that makes it more enticing!

Good luck and watch out.