Burritos by the Box costs $7.80 per person in my area and includes chips and salsa/guacamole (It's one bag of chips and side of sour cream for every two burritos ordered). The burritos are made with: cilantro-lime rice, vegetarian black beans, mild fresh tomato salsa, and cheese plus your choice of chicken, steak, carnitas, barbacoa, or vegetarian options
You can download the order form for your local Chipotle from their website.
Fine print: "Offer valid only for orders picked up on Sunday, February 5th, 2012. Minimum order size is 6 burritos. Maximum order size is 100 burritos. For orders of 50 burritos or more, please allow at least 24 hours notice. Limit one order per customer."