Richard collected baseball cards as a hobby. Richard had shared his interest in this hobby with his niece Susan, who was now also an avid card collector. At the time of his death, Richard's collection had a fair market value of $10,000 and an adjusted basis of $2,000, while Susan's collection had a fair market value of $5,000 and an adjusted basis of $1,000. Upon his death Richard's entire card collection went to Susan. With the death of her uncle, Susan lost interest in the hobby and sold all of the cards for $20,000. What is Susan's gain on the sale of these baseball cards? $5,000 $9,000 $13,000 $17,000