So, my wife and I decide to do some "closet cleanout" yesterday and I came across two U.S. Coin Prices Guides. . . 1970 Yeoman "Handbook of US Coins" (Twenty-Seventh Edition) 1981 Yeoman "Guide Book of US Coins" (Thirty-Fourth Edition) Some examples. . . 1921 Peace Dollar: 1970 = $20 (Uncirculated), 1981 = $2,800 (65), 2011 = $1,925 (65) 1928 Peace Dollar: 1970 = $65 (Uncirculated), 1981 = $1,450 (65), 2011 = $4,850 (65) 1881CC Morgan: 1970 = $50 (Uncirculated), 1981 = $240 (65), 2011 = $1,060 (65)
That's quite a bit of price fluctuations but it doesn't surprise me. I have 2 MS-67 1881-Os that were valued @ $27,000.00+ each on 9/12/2013 and on 9/13/2013 they were valued @ $18,000.00 each, a loss of $9,000.00+ each.
Please keep in mind that the "Uncirculated" used in 1970, the "MS65" used in 1981 and the "MS65" used in 2011 did not necessarily mean the same grade.