That's about the price for the small ones but they put out a ton of quality sound.
Look around, I got most of mine as "open box" discounts at best buy. Usually save about 10-15% that way.
The good thing about Sonos is that you don't need to dock your player to play music so you can keep your phone with you for calls or whatever. It's not linked via Bluetooth so you don't worry about the music cutting out if you run inside the house to take a leak or get beer, etc. hell, it will keep playing even if you drive to the store miles away!
The speakers are small enough to hide easily and have surround sound in your house easily and relatively affordable.
You can also set up an alarm or sleep timer on any of the speakers individually or as a whole or whatever.
With the big bar speaker, you can hook your TV or current A/V system to it and expand it even more.
There may be cheaper systems out there or even better systems, but from my uses on it, Ive been very pleased