Design 18 custom images to exact specification with unlimited revisions.

I'm looking for a designer to take over my web site at [login to view URL] ..... you will receive $5 per image I need 18 images done. But here's the catch - I need unlimited revisions!! Because the images are used by students to memorize things about herbs, I may send the image back and say this is not right, that is wrong. Its best if you always work with LAYERS and keep things simple to change, and you have strong background in making memorable cartoon type graphics (as for a story book). We will start with just 18 images, I may need 200 more of these done later if you do good work. Also I'd like you to save them as 1024x768 pixels and they have proper file names when delivered. Here are a few samples of graphics I like from our site that were completed by our previous designer. I will accept bid price of $90 and lower (for 18 images ,with unlimited revisions)