I save extreme ones for educational purposes. I started of with one roll that had what was odd in them. Then I moved them into four categories. Extreme machine doubling/extreme markers/strike though grease/extreme die cracks. I have these handy as I might need images for discussion. I can find them fast that way and its always nice to see an image that you hadn't seen before. What am I out? A few bucks. The rest I send them back into circulation except of the AU/BU 2000 and older. You never know when someone needs a nicer circulated coin. I always unconsciously know when one of these are under my scope. When you see how nice that coin is and you wish you'd find SOMETHING on it. But if not, I toss them into a tube for another day.