Best answer by Stanley_4
The Boost is a replacement for the long defunct Bridge, netter radios and newer version of Sonos Net.
Using a Boost to create a Boost Mode Sonos network will remove the Sonos load from your home WiFi and can lead to a more stable system. But so will wiring any other Sonos component so don't rule that out as an option, try it if possible and save your money if it works well.
I'd think about a Boost but also a Play 1 or Sonos One near the router if you have any use for sound in that location.
Don't rule out wiring multiple Sonos devices, the more wired the more robust the Sonos network. I wire everything it is easy to feed a wire to.