Shepherd's whistle
They are also produced commercially. Simple whistles may cost less than 1 USD in bulk; expensive ones may be quite ornate. They are commonly made of plastic, aluminum, stainless steel, silver, brass, titanium, Corian, jade, buffalo horn and other materials.
Wilson Audio
As of 2016, the most inexpensive stereo speaker from Wilson Audio, the bookshelf-sized Duette 2, is offered for about $20,000 US per pair (without stands), while the home theater WATCH center and rear channel speakers cost over $5,500. Their most expensive stereo speakers, the Alexandria X-2 Series 2, sell for $158,000 MSRP per pair and up, depending on finish. According to "Stereophile" in 2015, the average price of Wilson's product range is $69,325 per pair, in standard colors and finishing, and not considering potential extras.