Just started paying attention to prices. Here's what they were during the last couple of loads I did.

Cast Aluminum - .40/lb
Aluminum Breakage - .10/lb
Clean Aluminum - .50/lb
Stainless Steel - .45/lb
Aluminum Cans - .60/lb
Yellow Brass - 1.30/lb
#1 Copper - 2.80/lb
#2 Copper - 2.70/lb
Batteries - .10/lb
Prepared Iron - 250/ton
Unprepared Iron - 215/ton
Bailing Material - 205/ton

And I just called to find out the price of Steel as I haven't been separating it and I guess if it's not 1/4" or thicker it's just bailing. Otherwise it's the same as Iron. They just throw it all together. Guess I won't worry about starting to do the spark test.