Payment through PayPal

I am coding a customised module for users to register in an event. This event requires registration fee to be paid by a certain type of user. All other types of users are not required to pay the fee. The payment has to go through PayPal.

I know that the Ecommerce module can do this but apart from the Paypal part of it I have no use for the remaining features and hence want to avoid this. Is there any other PayPal plug in or module that I can use?