I've never found anyone that has done okay by scrapping a piano. Lots of work, with a small payout.
I did meet a guy once that said he scrapped a piano that the inside was brass, and not cast iron. He said that it paid $700. I'm not sure if this is true, or just a lie, but it is worth checking out with a magnet. A professional piano buyer and seller told me he has never seen a piano made from brass in his 40 years of experience.