Add a Purchase item

Just like when you go shopping!  Anyone that has earned enough coins can purchase these items. These are available to everyone on a first-come basis.   Consider setting the Cost relative to the “real value” of the item.

The Number of items is how many are available for purchase.  When there aren't any left, the item banner in the Store will change to Sold Out:

Fill out the rest of the form as needed.  Create Variants and use SKU's (Stock Keeping Units) if needed.  

Choose the Order method to determine how the user will acquire the item. 

Click Save to post the item in your Store.  Here's an example of an item set for Purchase: