You can retrieve your User ID and/or password here -> https://www.repriceit.com/forgotForm.do
If you just signed up, and you are not able to log into your new account, then it may be that your sign-up attempt was not completed successfully. During the sign-up process be sure to complete all the sign-up steps on PayPal. At the end of the sign-up process you will be brought back to a 'Thank You!' page on our site. If you did not get to this page, then your sign-up process may not have been completed successfully.
If necessary, you can sign up again here - https://www.repriceit.com/createAccountForm.do