I took in a trunk load of old intake manifolds off Hondas and Acuras to the recycler and I got $35. It was a LOT better than taking them to the landfill, both financially and environmentally. It takes a lot of electricity to refine aluminum. We should recycle as much of our aluminum as we can.
If you wonder why I had so many intake manifolds, the manifolds were replaced in order to fit the cars with aftermarket superchargers.