How to make product attributes appear as checkbox on the add-to-cart form? In Drupal Commerce how to make product attributes appear as checkboxes on the add-to-cart form? I want to see the sum of the prices of all checked products and add them all to the cart, when the add-to-cart submit button is pressed.

I wonder if there is tutorial, or - even better a module - for that?
The closest thing to what you're asking for is Commerce Add to Cart Extras.