Testing Your PayPal Account
The Following is the terms and conditions from PayPal regarding testing your live account:
You can not fill out your own information on the guest checkout form. Keep in mind, you cannot be both the buyer and seller in a single transaction - if any of the information provided on the guest checkout form, such as the name/address/email/CC/ etc, then our system can see that as an attempt to pay yourself (cash advancing) and stop the transaction from happening.
If you need to test your own integration on the live site, we recommend you have a friend or business partner do so using their own unique information.