Multiple Rebate type - One Vendor

Dear All,

Business Scenario:

Most of our Vendors offer rebate to us , based on the Quantity and Amount. 

We Procure and sell different varieties of items, some of the Items Value will be less and for some value will be more.

Vendor X says if we procure  1000 Quantity of Item, company is eligible for 10% rebate.

Also if our total Purchase transaction reaches $100,000, we are eligible for extra 5 % rebate.

How to achieve the above business case in our current JDE system?

Appreciate your inputs.

Regards

Basith