If you're after a thrifty option, this J.Crew Rollneck will fit the bill. It's a popular choice, while not very expensive. Another strong contender for your wardrobe is this J.Crew Sweater. While the price of this piece is not too high, it will definitely attract a lot of attention.
If you're looking for a happy medium, you're in luck with this J.Crew Crew-Neck Jumper in stock and waiting for you. You are bound to love this product. It's also worth taking a look at this J.Crew Turtleneck. This product is extremely popular and, just as importantly, not very expensive.