If you're a thrifty spender, this J.Crew Turtleneck will fit the bill. It's a popular choice, while not very costly. Another strong contender for your wardrobe is this J.Crew Turtleneck. While the price of this item is rather reasonable, it will definitely attract a lot of attention.
If you're looking for an item in the middle of the price range, look no further than this J.Crew Rollneck. This item doesn't cost the earth, but absolutely deserves a spot in your wardrobe.