If you plan on spending at least $67 at Staples between now and September 21, 2013, I recommend buying a Back to School Savings Pass. With a $10 price tag on the pass, you won't actually save money until you've spent $66.67 on eligible purchases. After that point, you will have saved the equivalent of your $10 purchase and anything else will result in savings.
Even though this is being called a Back to School Saving pass, you don't actually have to be returning to school to use the card. It's good on tons of office supplies. For the $10, you will get a card and a keychain tag. You can also sync the card with your Staples app on the phone in case you forget or lose your card. You will also still earn your 5% rewards in addition to these discounts.
The Back to School Savings Pass EXCLUDES the following products: Appliances and Housewares, Calculators, Case Paper, Decorative Accessories, Flash Drives, Food and Breakroom, Furniture, Ink & Toner, Safes and Security, Shredders, Technology, Tech Services and Copy & Print services.