I have tried to set this up, but cant seem to figure it out.....

We are a BBQ restaurant that sells meat by the pound, I know I can adjust item quantity during the order but is there an easier way to do it?
Right now I have setup 1lb pulled pork - and we adjust the number of those, but if a customer buys 10 I want to give a price break (which isnt working for me under the volume/discount feature)...

Ideally I just wanna setup an item called Bulk pork and then have it prompt for the number of lbs or the ammount, then multiply it out so the receipt shows.... x lbs pulled pork instead of numerous seperate line items...

Any way to do this?
Thanks in advance,
Tom Cuneo