Sorry for the "unfriendly" username, I'm just an employee (Yehoshua is my name!)
Here's the issue - we need to implement a kind of cumulative discount, similar to tax brackets. Thus, each bracket has a based amount (the discount up until that point) plus a percentage for any additional amount, up to the ceiling amount for that bracket. It doesn't seem to me that CRM 2013 (On-Premises) Discounts support that model. Is there a work-around? Is it supported in a later version of CRM?