If you're a thrifty spender, your best bet is this Sole Society Rucksack. It's a popular product, while not very expensive. Another good option is this Botkier Rucksack. While the price is not too high, be sure that this item will become a worthy addition to your wardrobe. You may also want to look at this Madewell Rucksack. This item is not expensive either, but it will make a difference in your wardrobe.