You can buy my Magento 2 extensions here using PayPal. All the extensions are 100% Open Source. They are licensed per domain.Installation is a free service.
How to buy
Each extension has its own topic or subcategory inside the «Extensions» category: https://mage2.pro/c/extensionsThere is a PayPal payment form for each extension.
All the licensing articles: https://mage2.pro/tags/licensing