Why does renew in IT Shop only work for some Products?

The Renew button in IT Shop only works for products that are avilable in IT Shop free of charge. Products that carry a charge require you to reorder the IT Shop license once it expires. The reason is that the payment process of the original order can’t just be repeated because the price of the product may have changed in the meantime. 

Note that student software generally does not require a yearly IT Shop license renewal.