I think you need to post detailed information to get more comments. What treatment is needed and what have you been offered for equipment?

About ten years ago, we had to replace an old system and called the local company (an Ecowater dealer) who had put in the equipment 20 years prior and serviced it annually. I was very disappointed that the price was more than double the cost of buying generic equipment and minerals on line. My recollection was that the labor factored to be $1500 or more and it seemed very high. Basically, it was two tanks (for softener resin and neutralizer materials), new controllers, and new salt hamper. Plumbing would have to be reworked but remain in the same spot, but the drain situation would remain (and just get screwed on to the tanks). I ended up buying the equipment and materials and hiring a plumber for a couple hours. It wasn't a fun diy. In my current home, I plan to ask a local water treatment guy who did a repair here. Some of the national companies seem to be premium priced, and have proprietary equipment. Basic tanks are cheap, controllers are variable, and materials vary based on conditioning needed (resins, minerals). If you have radon in the water, that's a whole other kettle of fish requiring specialized equipment.

Let's start with a basic question: Why do you need to install a water "conditioner"?

What is it that you are trying to solve?

Are you trying to soften hard water?

Are you trying to remove tastes, odors?

Are you trying to remove a certain chemical or contaminate? (Lead, cists, nitrates, etc)

Are you on municipal water or a well?