On January 1, 2012. Devo purchases a patent with a 7-year remaining life for $25,000. On January 1, 2013, Devo realizes that the patent will only last 3 remaining years. Yielding $9,000 of cash each year. What is the amortization expense during 2013 and the book value of the point on December 21, 2012? Devo borrows at 6%.