Early Sets
The uncirculated mint sets sold by the U.S. Mint from 1947 to 1958 came in cardboard holders that did not protect them from tarnish. These sets are harder to find in mint condition and command high premiums. Only about 5,000 to 8,000 of the first sets were produced, and they can sell for prices of $1,000 and more. These first sets came with two examples of each coin.
1959-1967
Sets have come packaged in protective plastic envelopes since 1959. In 1965 to 1967 special mint sets of greater quantities were produced instead of proof sets. Mint sets from this era usually sell for $25 to $50, with the mass-produced sets bringing about half of those prices.
1968-2005
The Mint continued to produce sets through these years with quantities in the 1 million to 2 million range. Values tend to be between $10 and $20.
Souvenir Sets
In 1982 and 1983 the U.S. Treasury packaged and sold souvenir sets in the Philadelphia and Denver mints in place of official mint sets. Each set also included a bronze mint medal. These are harder to find because they weren't as widely available and usually sell for $30 to $40.
Modern Sets
Since 2005 the proof set coins have been produced with a special satin finish that differentiates them from coins in general circulation. Recent sets have been produced with more coins and in lesser quantities and have generally sold for $20 to $30 on the open market. Current year sets can be ordered from the U.S. Mint at 1-800-USA-MINT.