The original mint price for the 1999 United States Mint silver proof set was $31.95. As of 2014, the current value of the nine-coin set is about $135, according to the experts at Professional Coin Grading Service.
The set includes the San Francisco-minted Lincoln penny, Jefferson nickel, Eisenhower dime, Kennedy half dollar and Connecticut, Delaware, Georgia, New Jersey and Pennsylvania state quarters. All but the Jefferson nickel and Lincoln penny were struck in 90 percent silver. A total of 804,565 silver mint sets were sold. The debut of the state quarters is responsible for the significant increase from the year before.