How can you setup price breaks when purchasing product from a vendor in Odoo? 

For example:

a vendor will charge $10/item when you order a quantity between 1-5 of that item, $5/item when you order a quantity between 6-10 of that item. How can you setup Odoo to recognize on a purchase order when the order qty is between 1-5 to reflect the cost of $10/item and when the order qty is between 6-10 to reflect the cost of $5/item?