How much can I expect to receive for a 2009 unibody MacBook pro?

if you mean you want to trade it in with apple to get a new Mac, please see Apple Trade In.

but I would think that a 13 year old Mac would be worth nothing as far as trade in with apple is concerned. but they will recycle it for free.

Hi,

Try to check at Apple Tread-In or eBay or similar services or shops who accept to buy your MacBook Pro.