It is completely free to register a PayPal account.

All PayPal accounts allow you to send and receive payments.

Personal accounts are mostly used for buying.
Premier accounts are used for buying and selling using your personal name.
Business accounts are for buying and selling using your business or corporate name.

With a Personal account, you can send money to almost anyone with an email address. You can send and receive some types of payments with no fees, and pay low fees for others.

If you registered a Business or Premium account,PayPal will charge a small fee when you receive money.

To learn more:
PayPal US -
https://www.paypal.com/helpcenter/main.jsp;jsessionid=KcSTQtKmJr33nYyGnGzMHvT4LFXXlrfZYR6JFT3yR9NtsVxWkj6x!-504723214?locale=en_US&_dyncharset=UTF-8&countrycode=US&cmd=_help&serverInstance=9003&t=solutionTab&ft=browseTab&ps=solutionPanels&solutionTopic=800041&solutionId=11927&isSrch=Yes

PayPal HK -
https://www.paypal.com/hk/cgi-bin/webscr?cmd=_display-receiving-fees-outside