AngularJS - Ionic - Parse - PayPal plugin : How to pass values to the buy function

hi i am trying to get a basic paypal payment setup within ionic. The products are loaded from a parse.com database all have an attached buy button. what i would like to do is pass the values from the products to the buy function. here is what i have now finally working using the example docs from the paypal cordova plugin.

the buy function within index.js

 buy : function () {
    PayPalMobile.renderSinglePaymentUI(PayPalApp.createPayment(), PayPalApp.onSuccesfulPayment,
    PayPalApp.onUserCanceled);
 }

the createPayment function thats called from the buy function

 createPayment: function() {
    // for simplicity use predefined amount
    var paymentDetails = new PayPalPaymentDetails("50.00", "0.00", "0.00");
    var payment = new PayPalPayment("50.00", "USD", "Awesome Sauce", "Sale", paymentDetails);
    return payment;
 }

the controller

.controller('PayPalCtrl', function($scope, ParseData) {
   // Open the login modal
   $scope.buy = function() {
   PayPalApp.buy();
   };  
})

html

<ion-list ng-repeat="item in items.results">
          <ion-item>
              <h3>{{item.name}}</h3>
              <p>{{item.price | currency}}</p>
              <button class="button button-positive" ng-click="buy()">
                  Buy Now
              </button>
          </ion-item>
</ion-list>

thanks for looking