Water Softener Installation Costs

What's "broken" on the one you have? There generally are not moving parts on a softener system with the exception of the electric head on the softener tank. The heads can be screwed off/on if it's as simple as that.

I bought a system from Springwell and did the install myself but with all the piping already in place in your case, it should be just a simple swap out (turn your water off). Assuming you can buy same tank/heights as previous ones, the connection points should line back up.

To answer your question, $3,600 sounds high when you already have the piping in place. Does that include the new materials/tanks or is that solely labor? If it's the whole system and all components, It's not that bad.

If you do it yourself, the tanks will come with pretty clear instructions from my experience. Make sure you follow any pre-soaking requirements.