Our shop sells various items, 1 item costs £2.50 but if you enter a code it reduces this item by £1. This is all well and good if customer selects just 1 item, how do i reduce the price by £1 per item.
For example if the customer orders 2 items the total cost is £5. The coupon only gives £1 off. I need it to give £2 off.

Any ideas?

Thank you.