The kinetic energy of the mass of exhaust gas carries it along the exhaust pipe, and causes a pressure build up ahead of the mass of gas and a partial vacuum behind it. This principle is used in a tuned exhaust system.
Culligan - $2352 ($2053 w/o R/O unit) Culligan Gold Series (10), Good Water Machine. If I were to look at price only, I would go with either the cheaper Ecowater system w/R/O at $2698 or the Culligan system. At almost $4k, the Kinetico system seems greatly over priced.
Choices of salt water softeners range from one-piece cabinet appliances to multiple-piece systems with separate brine tanks and are typically installed for $153 to $460 in the U.S. Features and capacity contribute to the cost of salt water units; with increased mineral-reduction and faster output come increases in price.