Two question marks are not enough!
Are you (he) looking for 6 speakers (5.1)
all wireless with the source being an AV Receiver or Processor? Or an L/R/C wired soundbar with wireless surrounds and subwoofer? And does $3K includes all of the speakers as well as the receiver, processor or control unit?
Of course, as far as wireless, each wireless speaker would have an AC outlet supplied power cable.
There is the
CineHome HD 5.1 wireless system from Enclave Audio that has an integrated center speaker/control unit, separate L/R speakers, doesn't require an additional receiver or processor and the control unit transmits to the other five speakers without needing a networked Wi-Fi router.
If you are more discerning on your speakers and need higher quality, it would most likely evolve into a more complicated and expensive package.
Steve