Hello,

My client is using the per unit shipping method for most of their products. They ship food and the containers are expensive so they have a large handling fee ($37.00) and then bill $3 per pound.

They also have a few items where shipping is included in the price of the product. For these I am using the free shipper module.

Everything is working as it should, but my client has a unique demand. They want the handling fee waived for every order that includes a free shipping item. The business logic makes sense: if the customer is already ordering an item with shipping included in the price, any additional items can use that same packaging and the customer shouldn't be billed an additional large handling fee. But, I don't think there is anyway to configure a rule like this in the Zen Cart admin interface.

I think I need to create a custom shipping module for this. Or maybe I don't need a custom shipping module but just need to alter the code that totals the shipping for an order. I am comfortable with programming in PHP, but I do not know where to start. Are there any good tutorials on this out there? I have searched google but I am not finding the information I need.

Maybe if someone can just point me to the file that totals the shipping costs for an order I will be able to figure this out, I am not sure where this happens.

Thanks