There is an especially intense game of Celebrity Property Traders going on right now, somewhat centered around those rascally Kardashian sisters—Khloe (the youngest one, who was until recently married to ex-Laker Lamar Odom) has just bought Justin Bieber's bland McMansion in Calabasas's gated The Oaks neighborhood for $7.2 million, according to TMZ. She needs a new place because she just sold her old one in Tarzana to Big Bang Theory star Kaley Cuoco. Bieber is moving out of Calabasas following a tumultuous couple years of tangling with his angry neighbors, including ex-NFL player Keyshawn Johnson, who has already left the neighborhood and sold his house to ... Kourtney Kardashian, who's selling her optical illusion of a house nearby. Whew. Exciting stuff. Bieber paid $6.5 million for his house back in April 2012. It's unclear where he's headed, but there's some talk he's interested in moving to Atlanta. Meanwhile, the house that plays the Kardashian house the family's television show is back on the market yet again, asking $6.25 million.