I watch copper the most.. I use this site, but these are spot
prices, not scrap. I don't know of any sites that list scrap prices.
You would have to call the scrappers to check.
I've got a good bit of copper, but I'm holding on to mine. I've had a
lot of it since before the price fallout, and I held on to it as I knew
prices would bump back up. And I'm not considering selling any time
soon. At this point, we still a bit below what it was selling for during
the peak in summer 08. About 3/4.. IE: copper is a little over $3 a
pound, and peaked a tad over $4 in 08.
At the lowest point after the bust, copper was about $1.20 a pound.
So I've tripled my money just hanging on to it. And I'm sure it will
nudge higher.
They list other metals too.
Kitco - Spot Copper Historical Charts and Graphs - Copper charts - Industrial metals