Shelley asks: How much are the state quarters worth today? How fast will/do they build value?
The copper-nickel State quarters being produced by the U.S. Mint are worth face value, that is 25 cents each, and are the current circulating quarter. Each coin is produced at the Philadelphia, (P) mint mark, and Denver Mint, (D) mint mark, in vast quantities, approximately 500 million coins each year.
Collectors try to acquire high quality pieces either from U.S. Mint sets, available from the U.S. Mint in the year of issue, or buy original rolls or bags from the Mint. There are also proof issues struck at the San Francisco Mint, (S) mint mark, in both copper-nickel and in 90% silver.
You can often get mint condition pieces at your local bank though they may or may not be of the same quality of as the Mint’s offerings. You can put together your own copper-nickel sets from 1999 – 2008 for a total of $25 per set (a total of 100 quarters from the Philadelphia and Denver Mints purchased at face value).
Since so many coins are available, I don’t expect that sets of business strike examples will bring much of a premium unless they are in unusually high mint state quality. It does seem that some of the proof issues have done fairly well already. For example the 1999 silver proof set, which includes all the State Quarters for 1999 in 90% silver, currently trades for about $100, well above its issue price from the Mint of $31.