1915 S $2.50 Panama-Pacific Commemorative Gold Coin was sold on Ebay. Winning bid: US $6,200.00.
Coin description:

Offering this 1915 S $2.50 Panama-Pacific Commemorative Gold Coin graded MS 66 by PCGS. More attractive than images suggest. There is a very small spot on the reverse well hidden below the Eagle’s right wing which may not be visable on the images provided.