Hobbyists wishing to obtain the 1998 matte-finish Kennedy half dollar from the U.S. Mint have just a short time to submit their orders. The 90-percent-silver half dollar is available only as part of a special two-coin "Kennedy Collector's Set" along with the 1998 Robert F. Kennedy commemorative silver dollar, and Friday, Feb. 13, is the deadline for ordering that set.

The Mint considers the matte half dollar a business-strike coin, rather than a proof. It is comparable in production quality to the matte-finish Jefferson nickels issued by the Mint in 1994 and again last year. Both of those coins -- particularly the 1997 matte nickel -- are bringing substantial premiums over their issue prices. Last year, however, the Mint capped the mintage in advance at only 25,000. The '97 nickel was available only as part of the 1997 U.S. Botanic Garden Coinage & Currency Set, and production was restricted to 25,000 of those sets.

By contrast, production of the Kennedy Collector's Set is limited only by the number of orders received before the deadline, and sales are expected to be considerably higher than 25,000 sets. That, of course, would hold down demand for the sets -- and their value -- in the resale market.

The Kennedy Collector's Set carries an issue price of $59.95. In addition to the matte-finish half dollar, it also includes the uncirculated version of the Robert F. Kennedy memorial dollar, which likewise is 90-percent silver.

The RFK silver dollar is being offered individually at pre-issue discount prices of $30 uncirculated and $33 in proof until Feb. 13. Thereafter, it will be priced at $32 and $37, respectively. Two-piece sets containing both versions of the RFK dollar (uncirculated and proof) are priced at $59.95 through Feb. 13 and will cost $64.95 after that date.

Subtracting the individual-coin price of the RFK dollar, the Mint is charging $29.95 for the matte half dollar. That is only about one-tenth the current aftermarket value of the 1997 matte nickel -- but since there is no limit (other than the ordering period) on the number of 1998 matte half dollars, it seems likely that the Mint will sell many times more of these, thereby curtailing their potential in the secondary market.