Most $5 Uncirculated Gold Eagles have mintages ranging from about 200,000 to about half a million. There is the exception of a few other dates in the series from the same denomination that also have mintages over a million or several million. However, for the most part, most mintages range in the lower hundred thousand.
The $5 1989 Uncirculated Gold Eagle is considered a common date in the series. Only examples in MS69 appear to be somewhat scarce but with enough searching, examples in this condition can be found in the market. Perfect MS70 examples are very scarce but they are out there and usually sell for a very significant premium over MS69 prices.