If the "mint marks" on the reverse are the letters "F" and "G," then these aren't mint marks at all, but the initials of Frank Gasparo, the designer of the half dollar's reverse. In that case, you have an ordinary 1989-P half dollar, which will run between $1 and $90, depending on the coin's condition, as of May 27, 2007. If the "mint marks" on the reverse are something else, then your coin is best evaluated by a professional coin dealer who specializes in error coins.
I'm guessing a bit here but you may be looking at FG, which aren't a "double mint mark". They're the initials of the coin's designer Frank Gasparro. The mint mark, if there is one, would be above the date. Blank = Philadelphia and D = Denver. (P wasn't used on halves until 1980).
In that case you have an ordinary copper-nickel half dollar worth 50 cents.
1 cent.
Check your pocket change. About 12.5 BILLION cents were struck that year. You'll find loads of cents with that date, and earlier.
The British currency is the Pound Sterling (GBP).
The British have never produced a Two Dollar coin.
A very common coin still in circulation, it's face value.
Britain did not produce a "Dollar" coin.
The coin is still in circulation and is face value.
$200
The British do not have a Twenty Dollar coin.
An Australian 1989 One Dollar coin (Proof mint set only) could fetch up to $12 AUD. A reputable coin dealer will be able to give a more accurate valuation.
A "one dollar" coin has the value of one dollar!
As of today 1-28-10 value is $107.72 the coin is one tenth ounce of pure gold.
A particularly nice one might sell for a dollar.
There is no such thing as a British 20 dollar coin. If you have a 20 dollar coin it must come from some other country (or even British colony)
The proof and uncirculated versions of this coin are both valued at $15.00 each.
the worth value of the liberty dollar coin is worth 50cents.
value of 1845 us five dollar coin