We’re not going to put a number on this page, and here’s why.
Two houses on the same street can need completely different equipment. One’s on city water and needs softening. The other’s on a well and needs iron removal, sulfur removal and a softener staged in order. Those aren’t close to the same job.
What we can do is tell you what actually moves the price.
First, what’s in your water. Hardness on its own is the cheap end. Iron and sulfur on a well is a bigger build with more equipment in it.
Second, how much water your house uses. A softener gets sized off your hardness and how many people live there. Undersized units regenerate constantly and wear out early, so nobody wins by going small.
Third, the plumbing. How far the main line runs from where the equipment needs to sit, whether there’s a drain nearby, whether anything needs re-routing.
Anyone who quotes you before testing your water is guessing at the first one and ignoring the other two.
The Cost Of Doing Nothing
Untreated hard water isn’t free either. It just bills you differently.
Scale on a heating element means the water heater runs longer to reach the same temperature. That’s on your power bill every month, quietly, for years.
Then the unit fails early. Around here that’s the most common expensive consequence, and replacing a water heater isn’t a small line item.
Add the fixtures, the appliances and the plumbing that all wear faster, and doing nothing has a price too. It’s just spread out enough that most people never trace it back to the water.