There is a difference, and usually little relationship, between the #11 world futures price, and US sugar prices, for several reasons. First, by definition the #11 contract trades in "raw" cane (never beet) sugar, not refined, white granulated sugar. Second, the #11 price assumes the "raws" are landed in the Caribbean, in bulk, and not packaged at a useful domestic location. Third, the raw price does not reflect import duties, fees and tariffs most countries, including the US, impose upon imported sugar.
The price difference between raws on the World #11 market, and the US #14 market, is typically 9-12 cents a pound, and is largely a measure of import duties and fees imposed on imported raws. These duties are, in turn, a reflection of "support" prices — minimum returns American sugar farmers receive for their crops.