If you're not planning on spending much, your best bet is this Barneys New York Scarf. It's a terrific item, while not very costly. Another strong contender for your wardrobe is this Scarf. While the price of this item is not very high, it will certainly attract a lot of attention. You may also want to look at this Dries Van Noten Scarf. This item is not expensive either, but it will make a difference in your wardrobe.
For something in the middle of the price range, why not check out this Bottega Veneta Scarf. While the price is very reasonable, this piece is an easy wardrobe update. It's also worth taking a look at this Loro Piana Scarf. This item is ultra popular and, just as importantly, not too pricey. And do check out this Amicale Scarf! It's a very popular item and good value for money.
If you're willing to splurge, then you won't be disappointed if you check out this Loro Piana Scarf. It's a costly but smart option.