it is definitely worth 15. actually getting someone to pay it may be hard. most will see it as a 2002 si with 33k, and not take into account the extras. it is one of those type deals where if the right person who can appreciate all you have done happens up it will be gone in a flash. good luck with the sale.
you would probably make more back by parting it out and sale the car stock. type x did his on ephatch and others. just a thought.