Through PayPal, you can pay with most major credit cards or directly from your bank balance, from almost anywhere in the world. You don't need to set up a PayPal account to pay with a credit card, and you don't need a credit card to set up a PayPal account.
If you don't already have a PayPal account and aren't paying by credit card, you should go first to the PayPal website and set up your PayPal account before registering a Project LRNJ account.
Registration costs $5.
All old registrations are still valid, and some have been upgraded to reflect changes in the registration system. You can claim or recover control of your old registration on the member page, or if that doesn't work, I have full records of all transactions and if you contact me by email I can fix it manually.