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.
Water Softener Prices. You may purchase a cheap water softener for $500 to $700 from a company like this one. This will do the job for you but the quality of this system may not be as good as higher priced water softener and purification systems. It will cost $1,000 to $1,700 for a mid-range quality water softener. You may buy a high quality, high volume water softening system for $2,000 to $10,000.