Actually....I don't remember or see a post where you said you would design it free or otherwise....
As for the 4-600 dollars if you look at this guys artwork...which would be customized with what I wrote him IE....2 versa's one hatch, one sedan on the back and then a club logo on the front left chest similar to this link.....
http://www.1maddmax.com/mdshirtscustom.html specifically the one for the Buford car truck and motorcycle show....I think that is an honest and fair price.
But hey...feel free to show us what ya got, like I Said...I Didn't see a post where you said you would design it