Match Quantity and prices are setup here. There are some variations based on your register type. Please follow this example to get you Match setup completed
Select Mix and Match Setup
Select Mix and Match Setup from the Promotions menu.
Enter the time that this Match price will be effective. This is done by entering a Start and Stop date. The Match price will work at the register beginning on the Start Date and ending the day after the Stop date. You can edit these dates at any time and upload the change to the register. The Stop date behavior is different depending on register type.