Well because you are quite new here, you should start with low prices. Those will attract customers and if you have enough and improved your skills you can slowly increase the prices.
I know someone who started here not long ago and his prices are around 15$ for colored, shaded artwork with proper background. Also he advertises on facebook for his work, but since you got more than FA it's fine. This person, btw., already has a lot of customers and because he is quite fast doing his work the list is updating all the time. I'm guessing he does 1 commission every 1-3 days.

Yeah, I was thinking about starting with low - probably very low - prices. Maybe 5 - 7 $ (or € and the dollar equivalent), not sure. Or even less for a start. Without a background, then or an easy background (like the night sky in one of my pictures). Just to get started. I have no clue how to get the word out though. The requests are helping to find at least some followers though I think. :3
Thanks for your advise!