Automated Dropship via paypal IPN

Design script powering "buy now" button that uses PayPal IPN to accept payment from customer then to place order and make payment using paypal with dropship vendor. Script will allow customer to purchase a single product without shopping cart. Script must allow merchant to use it on multiple products and multiple drop ship vendors on a single web site. Customer will be fed confirmation page with content designed for each drop ship vendor and payment type.