If you mean a 1990 Silver Eagle only Proof and bullion coins were struck in that year.
From 1986 to 1992, proof Silver Eagle coins were minted at San Francisco and these coins bear the "S" mintmark and have a current retail value of $20.00.
Bullion Silver Eagle coins dated 1990 were also struck at San Francisco but do not have mintmarks, the value of these coins depends on the spot price of silver at time of sale. As of today it's about $17.50.
No US $1 bills are dated 1990.
In mint uncirculated condition, a 1990 $20 note is worth $30. In normal condition, it is worth exactly $20.
10.00 dollars
A 1990-series $20 bill is too new to have any added value. Some of them are still in circulation.
A 1900 one-hundred dollar bill is only worth about $100. If it is in exceptional condition, it could bring in about $105.
50,000 or so depends on the condition if in excelent it can be wirth 75,000.
Fair market value as of 12/2008 is $9.
The approximate value of your coin according to Numismatic News Coin Market Monthly Price Guide for March 2007: 1990 Silver Eagle = $18.00
The 1990 Eisenhower Commemorative Dollar was issued in proof and in mint state condition. The value of each of them ranges between $20 - $30.
$50
An Australian 1990 Five Dollar (1oz 0.999 silver Proof)(Kookaburra), uncirculated and in absolute mint condition and original packaging, could fetch up to $40 AUD. There were 21,571 minted. An Australian 1990 Five Dollar (1oz 0.999 silver Proof)(Kookaburra)(Sydney Fair), uncirculated and in absolute mint condition and original packaging, could fetch up to $49 AUD. There were 1,000 minted. An Australian 1990 Five Dollar (1oz 0.999 silver Proof)(Kookaburra)(Albany Fair), uncirculated and in absolute mint condition and original packaging, could fetch up to $65 AUD. There were 200 minted. A reputable coin dealer will be able to give a more accurate valuation.
This is a bullion coin sold for its silver value, currently about $17/oz. The "$1" denomination is artificial.
This rare printing error has a value of $200-$300 in uncirculated condition.
The U.S. made no dollar coins in 1990.
Retail is about $30.00 maybe more if it's proof deep cameo
The last silver certificates were printed with the date 1957, and no US $1 bills are dated 1990. Please check again and post a new, separate question.
Do you mean the circulating dollar coin minted from 1971 to 1978, or the commemorative coin issued in 1990? The circulating coins are worth only a dollar each. The commemoratives are worth about $15.