conversations.from: human
conversations.value: Solve the math problem: John buys a lightsaber toy.  It is twice as expensive as all his other Star Wars toys combined.  If his other Star Wars toys cost $1000, how much money has he spent in all after buying the lightsaber?
conversations.from: assistant
conversations.value: The lightsaber cost 1000*2=$2000
  So he has spent 2000+1000=$3000