Modifying PHP, possible hire to complete job

Let me explain the situation. I have a site running as of now and I am having the database auto-updated each week by my distributor.

The issue that I am having is that when the site is updated, new products are added to the database with an inventory and a price of $0.00.

My goal was to redirect the click instance of the "add to cart" button to my contact.us page and add a note saying "email for price" whenever $products_price < $0.01, which also links to my contact.us page.

Thus far, I have completed the task of linking the "email for price" message to my contact.us page when $products_price < 0.01 and it is working fine.

However, out of all the modifications that I have done with the product_info, product_listing, currencies, languages, etc, I have yet to find a workable solution to creating an instance where the click event of "add to cart" button is linked to contact.us page if the $products_price < 0.01.

I have tried modifying all contributions that I have found at the OScommerce website and none have been successful thus far.

I need someone who is a bit more polished in php than I.

I am running OS v2.2 rc1

Thanks for any help, or anyone that is for hire, I am not above paying for the service.

Thanks!