The coin can be issued in 1990, 2001, or any other year – you will always see the same features. The only difference is the year on the coin the style of the coin stays the same. The United States Mint issues these coins every year.
Collectors refer to these as AGE or American Gold Eagles. So it is worth what one ounce of gold is worth.
All that means is that the value of the coin will change depending on the current value of gold. The 1990 $50 gold coin is pretty much just valued for its precious metal content.
