Scrap metal price is determined by the type of metal, location, quantity, and current market value. Copper sells for more than aluminum; scrap metal sells for more here in Dallas than in Mumbai, India; and a ton of scrap metal will sell for more than a few pounds.
As for current market value, you can follow the “spot price” of a given metal. Spot price is the price that companies pay for pure ingots of a metal. Kitco offers several helpful charts showing the current and historical market spot price for various popular metals here: http://www.kitcometals.com/charts/copper.html
Scrap metal categories determine price
Copper, lead, stainless steel, and most of the other metals we recycle fall into various categories that are used to determine value. Copper can be subcategorized into Bare Bright Copper, Copper #1, Copper #2, Copper #3, for example. Aluminum can be subcategorized as Cast Aluminum, Sheet Aluminum, Aluminum Cans, Extruded Aluminum, and the list goes on. Sometimes these subcategories are obvious, but sometimes there can be some controversy. One scrap metal recycler may classify your copper as Bare Bright Copper, while another classifies it as Copper #1. One may grade your metal as cast aluminum, while another grades it as “pot metal”—which is worth about 40% less!
For more information about scrap metal categories, take a look at our “Metals We Buy” page.