SEO mod for e-com site

I need a perl programmer to assist in integrating mod_rewrite into existing shopping cart. I can purchase an SEO script to do this for my cart for $100.00 but since I have already written effective mod_rewrite rules that are working perfectly on the links that I am able to hard code into the site I only realy need to have the cart software produce URLs that are compliant with my rewrite rules so I am setting a ceiling of around $50.00 for this code modification. This task should be quite easy for an experienced perl programmer. There will be repeat business for the winning bidder.