If you can do it yourself, you can get one a Home cHeapo, Lowes, Menards, etc. for probably around $300 or so. They really aren't too hard to install, they just need 'spliced' into your water supply line and plugged in. If you can't do it, bribe someone you know with pizza and beer who can, or buy one yourself and hire a plumber to install. It should take them less than an hour.
If you use your outdoor spigots a lot, consider having the softener bypass those.
Most of the places that will do it "professionally" overcharge by a boatload.
Their benefits are many. No more scale in the shower/tub and door. Water heaters, dishwashers, faucets, etc. last so much longer with them. Easily orth the investment and the few bucks a month in salt.