Collectors love U.S. Mint proof sets as they combine all the years circulation coins, minted in finest quality proof form, all in one contained set. Even more coveted are these special silver sets containing 90% silver dimes, quarters and half dollars. As well as having precious silver content, these special sets have only about one-third of the mintage of the years regular clad sets. Those lower production numbers make these sets tougher to find and all the more desirable and valuable. And these 1995, 1996, 1997 and 1998 sets, now around two decades old, were the very last to feature just five coins. The next year the extremely popular Statehood quarter series was introduced and that added more coins and a second holder to all U.S. proof sets.