I am an anime artist. I have mastered my sketching and also mastered colouring it. I give my full effort in all the art works I make. I do A4 as well as A3 size art works.
I take a bit more time but thats because I make the art perfect so that no one needs to complain and regret for it later.
Just because I am a new commission artist I also charge less on my art works.
The cost grows as the size and number of character increases.