Occasionally as with the 1996 Olympic dollar coins, they cut cancel them and sell them to collectors. The mint sold dies up until the early 1970s that had been cancelled, and they tend to go back and forth on selling them. Now when they sell the State Quarter dies they grind off the whole design part of the coin, leaving just blank metal. Other than those State quarter dies that they sell to collectors, the rest are recycled. Frankly I cannot imagine buying a blank die. I wouldn't mind having one of the 1968-S cent or nickel dies though.
yOU NEED AN AVITAR dd:They have mineral/foundry/labor/coal/and now old dies? I thought they didn't even like capitalism until lately. ..or was that just easy to type? oops...forgot to mention I'm glad there is something we can sell "them" for a change.