Hi, I want to write a module in which I should alter the prices displayed after that customers click on "Add to cart" button. I have to edit prices in function of the quantity ordered by other customers. In other words, the customers, after have clicked on "Add to cart", see the prompt with the new cart in which the module has modified the prices. The new prices should also be inserted in the cart (server side) so that when the order will be confirmed, it will contain prices as modified by the module.
I don't know how to achive this result. Any idea?