If you're looking for in-game bells, you could probably get 30-40 million just for a character alone, around 50-60 mil for a character with a simple background, and probably around 80 mil. for a character with a detailed background.
This is for full colored and shaded characters though. Sketches or character with coloring, but no shading/lighting would sell for a lot less and if you're doing more then one character, you can take the prices x1.5 or x2
I love your style! I'd recommend selling for TBT instead of IGB since TBT is way easier to exchange. TBT is the site's currency which can be swapped with other members for IGB. 100 TBT is about 20mil IGB. You can always do both IGB and TBT prices though.
Ahhh your art style's really cute! I like how you color! For IGB, I agree with cheesie16's prices. I do agree it may be easier to go for TBT like Pokemanz was explaining above. I think 200-600+ TBT would be a good range, especially if you can scan them in.