Tom writes: Where can I get the current value of Proof and Uncirculated coin sets from the U.S. Mint? One of my relatives has several sets from 1970-1997
You can try a publication like Coin World. You should be able to find a copy at a newspaper and magazine shop. The paper lists price trends for coins and contains many ads, including ads for modern proof sets.
One comment about modern proof and mint sets. Most of them trade below their issue price, which makes buying them in the secondary market a better deal then buying them from the Mint. Even some of the high-flying issues seem to cool off quite a bit over time.