If you are selling (or intend to sell) something online then you are going to need a payment processing system.
One of the simplest methods is to use Paypal.
Paypal can provide payment processing and even a shopping cart system. You can create payments buttons for single products or for subscription (ongoing) payments for your product or service.
We have used Paypal for years and can help you to integrate Paypal's shopping cart system or "Buy Now" buttons.
If you are trying to sell your product or service online and want to gain more customers and more sales please contact us for a FREE assessment of the possibilities for your business.