May or may not be high depending on condition. Assuming it hasn't been used all that much, and assuming you've looked into "new" cost, it may be reasonable. Remember that a new 50hp motor alone will be around $4K, if not more.
Retail prices of Caribe 13'ers look to be between about $9K and $12K, and that's probably less motor, certainly less trailer.
http://www.co2inflatables.com/Caribe%20Price%20List.pdf
jky