If you're a budget-conscious shopper, this Corsia Backpack will fit the bill. It's a foolproof choice, while not very expensive. You can also take a look at this Piquadro Backpack. It's a product you'll fall in love with which also doesn't cost too much. You might also want to consider this Parentesi Rucksack. The price is very reasonable, but the effect on your wardrobe will be pretty fantastic.
For something in the middle of the price range, we've got your back with this Frye Backpack. This piece is bound to become a total wardrobe staple. It's also worth looking at this Piquadro Rucksack. This piece is extremely popular and, just as importantly, not too pricey. And do check out this Rucksack! It's a very popular item and good value for money.
If you want to treat yourself, then you won't be disappointed if you check out this Prada Backpack. It's a costly but smart option.