conversations.from: human
conversations.value: I need a clearer understanding of how to solve: Marilyn wants to buy a pair of boots online. On Amazon.com, the boots cost $16 and shipping costs $4. On eBay, those same pair of shoes are only $13, but shipping costs twice as much as it does on Amazon. How much more expensive do the boots work out to be on eBay?
conversations.from: assistant
conversations.value: The total cost on Amazon.com is $16 + $4 = $20
  Shipping on eBay costs $4 x 2 = $8
  The total cost on eBay is $13 + $8 = $21
  The boots cost $21 - $20 = $1 more on eBay