I need a cover art for an eBook

Estimated duration: not set
Description: Hi Jason, Can you give me a price on cover art for a book?
I wrote a book for self publication on Kindle. It is a children's book (one of six book series) The book is called "Kieran James and Osiris Conspiracy" and it is set in USA. It centres around a boy called Kieran who is 13 yo. He is a cross between Ben Tennyson of Ben 10, Johnny Test and Hiccup from the movie 'How To Train Your Dragon' as a character. He joins a US government agency called Office of Paranormal Investigation (OPI)which uses cool gadgets like X-Tazers, Z-Shooters, Ghost Goggles and Info Specs to capture or kill Ghosts, demons and monsters. The Special Agents for OPI are all kids under sixteen except for the trainers and directors. OPI is like a cross between Men in Black and Ghost Busters. Kieran joins a team, Team Phoenix, consisting of Clarence, Amy and Megan, who are like Fred, Daphne and Velma from Scooby Doo, as well as Spud the alien who looks like Dobby from Harry Potter. His trainer is Agent Malcolm who is a cross between Agent Bubbles in Lilo and Stitch and Morpheus from Matrix.
The story follows how Kieran matures as a Special Agent for OPI and works to stop all out alien invasion of Earth.
I will be happy to tell you more about the story if you wish.

Thanks
Junichi Imura