You can put additional items at the bottom of an item's page. Such items are called accessories, and like items in groups, they don't have their own page. Everything about them (including their order button) appears on the page of the item that contains them.

Create an accessory to an item in Store Editor

1. Sign in to your My Services page.
2. Click the Store link.
   
3. Go to Store Editor.
   
4. Navigate to the item page to which you wish to attach the accessory.
5. Click Accessory from the Editor Toolbar.
   
6. Fill out the fields on the Edit page that comes up and click Update.
   
   The accessory will display on the page below the main item.
   
7. Publish when ready.
   

Note: Accessories are leaf items. If an accessory is missing something, like the order button or image, check under Config on the Advanced Editor toolbar to make sure they have those variables selected in the Leaf-contents-elements field.