Edit: This person is not a PayPal employee, below link changed to a search
You can try this fully functional shopping carts for paypal
This shopping cart provides all necessary features including discount prices, inventory management, integrated shipping cost calculator, secure digital goods delivery, discount coupon codes.
Shopping cart is easily managed via secure administrative area. Integration of the software into existing website is easy with the use of flexible HTML templates. Shopping cart also provides means for order management, automatic e-mail notifications. Shopping cart is search engine friendly. Affiliate version is available that enables one to set-up multiple affiliated shops on their website. Shopping cart uses PayPal as the primary payment gateway.