If you're a budget-conscious shopper, your best bet is this BDG Sweater Dress. It's a popular product, while not very pricey. Another wonderful option is this Sweater Dress. While the price is competitive, be sure that this piece will become a worthy addition to your wardrobe. You may also want to look at this Urban Outfitters Sweater Dress. This item is not expensive either, but it will make a difference in your wardrobe.
If you're looking for something in between pricewise, why not opt for this Elliatt Sweater Dress. While the price is very reasonable, this item is an easy wardrobe update.