I would recommend approaching DiscountASP with questions about discounts for Sitefinity customers.
As Radoslav mentioned previously in this post, while the older versions of Sitefinity run fine on the DiscountASP.NET hosting platform, the newest v4 is experiencing some issues when running on our hosting platform. DiscountASP.NET and Telerik are working together to improve the customer experience with Sitefinity.
I suspect that due to the above, currently the deals with DiscountASP.net for Sitefinity customers are put on hold, but I might be wrong.
Grisha 'Greg' Karanikolov
the Telerik team