Depends on aplication.
High Voltage Power lines: Aluminue is far cheaper. Aluminue requires a bigger wire for same voltage, but the bigger wire still weighs less. This means they can streach it further, poles are cheaper, and they need less poles.
The stock market: Not sure, not a market expert, but since the market crashed a year ago, I would say low.
Heat Sinks in computers: Required for heat pipes in notebook computers, but in desktop copper is high cost.
Whats the application?