Pattern for adding/removing an item within a form

I've looked around and can't find any pre-existing examples/patterns of an easy way to inline add/remove an item within a form.

The scenario is during a process for me to add a new customer to my account, I can add or remove any number of products and change some options on those products.

Screenshot:

Do you know of any UI patterns or live examples that has that functionality?

To me, this form clearly has some confusing areas but before I work up a solution, I'd like to know if there any existing best practices. Any other general thoughts on the form above would be welcome as well.

Thanks!