When I was in high school in Austin back in the day, you could get a Sonic Brown Bag special for $4 when they were running the promotion. That's 2 burgers, 2 fries, and 2 drinks, for $4. My buddies and I would hit it up at lunchtime every day for the entire duration of those promos, which was usually a month or so per semester, and we would feast.
But then they started sponsoring AISD by providing book covers, along with ButterKrust Bakery, and Big Red soft drink. But on the Sonic book cover, they'd include a coupon for a burger/fries/drink combo for $2. On the first day of school, my friends and I raided every single pile of Sonic bookcovers in the school, and cut out that Sonic coupon from each one, and then discarded the mangled and molested book cover carcasses back on the pile. We had hundreds of those coupons and then we didn't even need the Brown Bag Special. Twas glorious.