What is a good price for complete site design on Cs-cart 2.x?

I am planning to redesign my website based on Cs-cart 2.2.4 and give it a complete new and customized look. I plan to get a PSD designed first for my website and then get it sliced and coded through a cs-cart expert. What would be a good price to pay only for the PSD design part? My site would have 3 main pages and 7 sub pages to be redesigned.