Now I've taken several commissions and feel confident in setting a general price range.
Well, only for the Illustrator bits at the moment, but this'll eventually get updated with more options...

Digital - Vector - Things drawn in illustrator.
Examples are Celebi commission, Tengu, the ivysaur eating pizza, etc.
Small sizes are $5 (Celebi commission, Ambipunch)
Medium sizes are $10 (Prize Charizard)
Large sizes are $20 (Tengu)

These are single character rates, for extra characters expect to add roughly $5 (could be less or more depending on size of the extra character, etc.).
For a monochrome background, add $5 and for a color background add $5-10 depending on the level of detail wanted.
It also could cost slightly more overall depending on subject matter and complications and stuff, but I am probably going to be fairly cheap for a while. I take what I get.
And of course, tips are appreciated ;D but not necessary.

Note me on dev-art or comment me here, email me (katagi at gmail dot com), contact me on MSN Messenger, or whatever. Paypal only (unless you want to snail mail me cash, which is fine, but I can't be held responsible for stolen or lost cash).

Oh and! even though only Illustrator style is listed here now (since it's the only one I've gotten decent commissions for) don't hesitate to ask about other styles, for instance pixely (whiptail hatchling, symmetry), pixel-art (Furc portraits), or even traditional sketches. :] Thanks.