Re: buying a water softener
You didn't mention anything about your family size which would directly be tied to the amount of softening capacity you need. I was looking at several different water softeners recently and for a family of 4, you couldn't beat the Sears Kenmore line for price -- especially when they have one of their special sales on water softeners. By far they were the most reasonable at $400-$700 for some of the different models they had. I figure the technology for water softening is basically the same, so you might be able to 'buy' more bells and whistles on a softener but not really get any more value. The unit we had was a 20 year old Sears Kenmore unit.
Two things though, if you're on a well water system you have to carefully control the chlorine as it will definitely shorten the life of the water softener. The chlorine causes the softening granules to clump and clog up on the inside where the softening is done.
Second thing -- our old softener came with the house when we bought it and I discovered that by filling the salt resevoir up as indicated in the directions for the periodic purging/cleaning of the softener tank (regeneration, they call it) that the water was way too soft for our tastes. I finally went to throwing in the amount of water softener salt to get the water softness to where we liked it right before doing a regeneration.