If you want to sell from Content component it is very possible. For example you are a hosting company and every content item is a hosting plan. And you want to have a Buy Now button for every plan. Or you are a tour operator and every content article is a tour description and you want to have an Order Now button there.

For that you need to create a URL type field. Then, when you create an article insert bill URL into it.

Note that you can append amount and description parameters to the URL. For example if you want one bill title but different amount.

Yes, that is easy. We have technical article here on how to integrate Bill with other components on plugin base.

Bill is very flexible and it has one feature that allows you to let customers purchase the same bill endless (or limited) amount of times. This type of bill is more like "Product". As a bill number you need to enter product SKU which will be always the same for every transaction. More than that, in report center you can get a diagram on this product (bill) sale process.