There is no additional charge for using Amazon Virtual Private Cloud, aside from the normal Amazon EC2 usage charges.
If you choose to create a Hardware VPN Connection to your VPC using a VPN Gateway, you are charged for each "VPN Connection-hour" that your VPN connection is provisioned and available. Each partial VPN Connection-hour consumed is billed as a full hour. You also incur standard AWS data transfer charges for all data transferred via the VPN Connection. If you no longer wish to be charged for a VPN Connection, you simply terminate your VPN Connection using the AWS Management Console or the DeleteVpnConnection API.