A few notes:
1. As Wayne pointed out you should be sure to use Coinstar machines that waive the fee if you get a gift card. They have them in my area with gift cards to Lowes and Amazon (they have others but I don't use those). Save them up and then turn them in when you need something from Lowes for the house. They also have gift cards to Old Navy, Borders, JCPenney, Starbucks, and many other retailers.
2. Many of us save the coppers because they are currently worth 3 cents each and are probably only going to go up due to rising copper prices. It is true that there is a melt ban on them but even so, people will pay a premium for them on EBay and CL. Some day they may be worth 10 times what you paid for them.
3. I sort copper pennies using my metal detector. Two out of my three detectors can tell the difference between a zinc penny and a copper penny. I just put the detector on the ground and wave the pennies over the coil. I can do about one penny per second (not counting unwrapping the rolls).
4. The pros use a Ryedale machine to sort pennies. But they cost several hundred dollars. I'm not that into saving copper so I just use my detector. I do about one box every couple of weeks. But if you really want to cull some serious copper then the Ryedale machine is the way to go.
5. I average about 25% copper pennies per box. That's 625 coppers for each box I do. At 3 cents each, you're talking about $18.75 worth of copper that you only paid $6.25 for. A 200% profit. Sure, you aren't going to get rich off of it. But if those pennies go up to 5 times face value you are looking at $25 profit per box. And pennies at 5 times face value could be only a few short years away if things keep going the way they are going today.
Another way of looking at it is that by dumping your copper pennies down the Coinstar machine, you threw away about $37.50 worth of copper profit in your three boxes.