Hi @AJ1971
Perhaps I’m not understanding the exact requirements here, but I don’t think you can change the price of products or attributes on the front-end like this.
If I understand, you need to charge a setup fee per product, but not per quantity.
Perhaps the volume discounting brackets could work here (if customers might only purchase a limited quantity).
Otherwise, I’d look to have a separate “Setup” product that you programmatically add to the cart for each product in the cart.
Failing that, perhaps the Shipping options could be used to achieve this… unless you are already utilising shipping.