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.
But with culligan you lease the equipment and pay monthly or quarterly. Do yourself a favor, find a private water treatment contractor and have them test the water properly and install a system that requires only one yearly maint. A softener would prob run you $1100-$1600 depending on size.