It wasn't many years ago I considered all three 1968 cents quite common in Gem. Of course when I say "common" I mean that the total existing in the world was betwen about half a million and one million. That was back in the early-'90's and there might have really been so many back then. I did not foresee how unkind the years and mint packaging would be to them. Their numbers in mint sets keep dropping because the sets are being destroyed by a world that doesn't care. Their numbers in rolls aren't that great as evidenced by the high roll price back in 1970. These sold for as much as $2.75 or about $20 in today's money. Roll coins are not heavy in Gems for these dates. Mint set coins have turned pretty badly. About 60% of the D and S are corroded now. There aren't many sets left and 60% are corroded. The Philly is far worse and for practical purposes they are "all" corroded. Only about 5% aren't ugly but even the 5% are carbon spotted. My concern isn't only that these modern coins won't be there if anyone ever wants them but every year that people ignore them another 2 or 3% of the few survivors bite the dust. If the current generation of collectors fails to preserve some of these coins they just won't be there. "Countless billions" indeed! People just don't understand the concept that only the coins you see everywhere are common. 1976 quarters are common in Unc. But 1982-D cents that are well made and pristine weren't even all that common December 31, 1982 and virtually all of them are gone now.