There are probably other sites out there like this,about the Prima Music Company.
They offer discounts and wholesale items to piano teachers. You can also create and manage your studio list. They also help save your students money on books by giving them a pass code under your studio name. They then have to create a free membership log in and can enter your pass code to save money on books. Also, you earn discounts based on the sales you sell. Unfortunately, I have not gone up yet, but hope to soon.
Some of you are more well established with your students than I am at this point and have a large studio, so at this point you would probably benefit more than I do from it.
Anyway, hope this is helpful.