You have a few options.
First, you can add paypal “buy now” buttons anywhere on your website. All you need to do is create your buttons within Paypal, and then copy/paste them wherever you would like them on your website.
Second, you can use the Photo Gallery as a product catalog and add paypal “buy now” buttons into the description area, which accepts HTML. This is actually the most popular way to set up a product catalog and also to sell products. It’s super easy.
Lastly, If you plan to sell a bunch of items, it would be best to use an eCommerce platform such as Wazala or Ecwid, both of which you can embed into your IconoSites website. Here is our tutorial on Wazala –http://www.iconosites.com/blog/2012/01/how-to-add-ecommerce-to-your-website-iconosites-website-builder/ .