To which quantity discount are you referring?

Per product, or by category?

Well, either way it's pretty straightforward. You have a quantity FROM and a quantity TO, then the discount amount, which can be either an amount per item, or a percentage.

If you're doing quantity discounts, don't forget to put in the "1" through.... for example, if I was going to do $1.00 off per item on quantities of 25 or more, I would do:

FROM 1 TO 24 0.00

FROM 25 TO 99999 1.00

... and that would subtract $1.00 per item when the quantities were between 25 and 99999.