If you'd rather not spend much, your best bet is this Express Cardigan. It's a wonderful piece, while not very costly. Another strong contender for your wardrobe is this Express Crew-neck Sweater. While the price of this product is rather reasonable, it will surely attract a lot of attention.
If you're a bargain hunter, consider choosing this Express Sweatshirt. While the price is very reasonable, this item is an easy wardrobe update. Also take a look at this Express Hoodie. It's an attractive option both price and quality-wise.