Because the list is generated dynamically, I don't recommend referencing buttons by UID. And definitely don't hard-code UIDs in events, because they may change.
Every object in the grid is linked to a record in JSON through the DataBind plugin. For example, when a button is pressed, you should be able to access the name of the product and its price using these expressions:
Button.GridViewDataBind.get("title")
Button.GridViewDataBind.get("price")
Or using the JSON object:
JSON.Get(Button.GridViewDataBind.index & ".title")
JSON.Get(Button.GridViewDataBind.index & ".price")