If you're a thrifty shopper, your best bet is this Bric's Rucksack. It's a great product, while not very costly. In this price range, you can also check out this Herschel Backpack. It's also a popular item and won't break the bank. You may also want to look at this Kenzo Backpack. This item is not expensive either, but it will make a difference in your wardrobe.