Backpacks at Staples are marked between 25% and 50% off, plus you get the full purchase price back in the form of Staples Rewards. These rewards will be issued in October and I was told that they may be used on anything in the store.
The backpacks were more expensive than the ones at Walmart and even the ones that I looked at at Meijer---HOWEVER---if you have a high school or college aged student who needs a backpack, you might consider the Staples deal. The backpack I found for my daughter is quite a bit larger than what you normally see. It looks quite durable and waterproof (she needs a strong one for all her heavy textbooks), but most important, in her opinion anyway, it is very attractive. And we'll get the entire cost back in the form of Staples Rewards.
They did have some younger childrens' backpacks there as well. I didn't check the prices but you might do better doing the Kelloggs $10 off deal (find one $10 or less and it's free). But as I said, if you need a larger, more durable one for an older student, you might check it out.