When you create a new product, we will instantly generate an embeddable buy button for you which can be found in the "Embed this product" tab.
Here is an example of a Shoprocket site using simple buy buttons. As you can see, there is no sr-block as there would be normally, but instead a sr-add with the ID number of that product.
Of course, your code snippet can be modified slightly. By default, the link will say **Buy**, but you can change this text to whatever you like, such as **Buy now**, as seen below.