I have previous experience with illustrations, check "Mascots" part of my portfolio for examples of my illustrations work. I'd need to know exactly what type of illustrations do you want, and if they really are simple I would be fine with what you offered, 50$ per book. Time wouldn't be an issue because I am confident that I could make a full set of illustrations for one book in a week or less. Contact me via Chat to discuss more details about the project!