We already have website and PayPal buy button for a product, we just need a script for coupon code so people can get 20% discount with the code.
If you have any questions, please contact me anytime.
4 freelancers are bidding on average $38 for this job
pretty simple... heres a link that can help you or anyone interested in doing this. http://www.willmaster.com/library/features/paypal-buy-now-buttons-with-coupon-codes.php