I think they're usually cast iron, so I'd guess maybe 300 pounds? Here that would be $42.
If it's an old one with ivory laminated keys you can make more selling the keys.
i fell for this once, and will never do it again. had to pay to get rid of the wood because it was painted. i put it right up there with scrapping a camper. also you need a team to move a piano.
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.