This is the deal:
Customer adds a product to the cart. Then they start the usual checkout procedure. They go to check the cart. Then they enter a coupon code... and this is where the modification needs to take place.
As soon as they hit apply button. I want them to see the discounted price right there next to the original price(strike through).
I'd like it to also work on checkout and product pages.
It is important that the TAX is taken into account. Our shop has prices including VAT for EU countries and all other countries have the prices excluding VAT.
Please see the attachment to get a better idea.