average cost per copy
The copier people will tell you that desktop printers average $0.05 to $0.06 an impression and they could be right. Of course your printer could very easily be costing you $0.01 an impression too and you copier could be at over $0.10 an impression. It all depends on utilization and total cost. The largest difference between the two is toner yield because it tells you the toner cost per impression.