These were not made in that year.
A normal 1991 S proof set is worth $9. A 1991 S proof prestige set is worth $51.
1983 to 1997
Yes. It's fairly scarce. Numismedia quotes a market value of $135 as of 04/2009
4 types of United States Mint Proof Sets were made in 1992. The clad 1992-S Proof set has a current retail value of $8. The Prestige set that has the Olympic half & dollar in it is $40.00. The regular silver set is $29.00. The silver Premier set is $31.
A 1992 Prestige set is currently worth about $60.00
A 1984-S annual proof set is worth from $8 to $11.00; also, in this year, the US mint produced 1984-S Prestige Sets - its value ranges from $23 to $30.00.
The complete 1963 mint set has a value of $40.
80.00
Simple marketplace rules - supply and demand. Ask anyone who bought a house in the last two years, or who is trying to unload a gas-guzzling Suburban Useless Vehicle.
The value of a United States mint coin set varies. It needs to be in its original packaging with appropriate documentation. A 1956 US mint set has an average value of $40.00.
Numismedia quotes a market value of $34 as of 04/2009
Current retail value of a 1972 Mint set is $4.00 Issue price was $3.50