We have a discount schedule that applies to a specific group of Products for Accounts that are Supply Houses.

Looking at the documentation, it seems like the only way to accomplish this is by having a Pricebook just for Supply Houses and restricting the discount to that. 

I'd really like to avoid creating another pricebook and, ideally, would like the discount to be applied automatically to quotes where the Account's type is Supply House (on the Quote, the Distributor field is automatically populated with the Account).

Is there any way to do this without creating another pricebook?