Miley Cyrus is Back to Extensions

Miley Cyrus just updated her hair last week (see left pic.), but she's already sick of it! The 17-year-old starlet is back to her long extensions, and they're rumored to have cost her $24,000!

An insider says, "Miley bought the best hair possible, and then had it dyed to match hers exactly. Her hair is an investment."

..Sounds like quite the investment to us, but now that Miley has been named one of 2010's Most Powerful Celebs , we're sure it aint no thing!