The documentation is being updated. There may be incomplete sections.
Is Gaea subscription based?
Do I need to pay a maintenance fee?
How do I upgrade my Gaea license to Professional or Enterprise?
Can I purchase Gaea with a credit card?
Yes. To pay using a credit card, instead of clicking the large "PayPal" button, press one of the card icons of your choice to open a popup window for that payment method.
If you are already in the popup window, do not log into your PayPal account. Instead, simply "Continue as a Guest" and you will see which credit cards PayPal accepts.