IF YOU CAN FIND ONE, a fine first edition in dust jacket of Frank Herbert's Dune (1965) is worth over $500, as are Philip Jos,e Farmer's first novel A Green Odyssey (1957) and several titles by Robert A. Heinlein, whose most famous book, Stranger in a Strange Land, (1961) seems to increase in price every time a copy is sold. Recently, a set of the three galley proofs for J.R.R. Tolkein's The Lord of the Rings trilogy changed hands for a stunning $13,500. Clearly, the collecting of fantasy and science fiction is hot and getting hotter.

Until the 1970s most sf material--pulp magazines, limited circulation fan magazines, correspondence, and especially hardcover books--was traded, collected and preserved by fans. Fans even founded the publishing companies, such as Fantasy Press and Gnome Press, that brought out in hardcover most of the first books or early works of every major sf author, including Isaac Asimov, Arthur C. Clarke, Ray Bradbury, Robert A. Heinlein, Edward E. Smith, A.E. van Vogt and Theodore Sturgeon.

During the 1950s and '60s these same fans haunted second-hand bookstores, which often yielded unlikely treasures. Pulp magazines, first editions, occasional early paperbacks could be discovered in any major city, and practically everything was within the budget of a teen ager. As sf proliferated in the '60s, it became still easier to collect; for although the pulps began to disappear, paperbacks became superabundant. And in those golden days, the prices never seemed to increase much.

Then, at the end of the '60s, the sf and fantasy field boomed. The popularity of 2001: A Space Odyssey, Dune, Stranger in a Strange Land, The Lord of the Rings, and Star Trek, together with new academic interest in sf as a significant development in contemporary literature (a still argued and still lively controversy), generated widespread enthusiasm for sf outside the inner circles of loyal fans. By the early '70s sf became one of the hottest fields in book collecting, and has remained so for more than a decade.

As a result, some fans found themselves holding, if not gold mines, at least collections of precious metals. After having remained stable for nearly two years, book prices trebled within a year or two, then increased steadily for a decade--after which they doubled or trebled again. Most desirable sf books are now worth 10 or more times what they were in 1970.

Profiteering is rife in this new market, especially the proliferation of artificial rarities: limited editions, signed editions, deluxe editions, all of them designed to fill the shelves of speculators who hope these big-ticket items will be carried upward in value along with the authentic scarcities. Yet the true fan presses still exist, cropping up all over the country, soliciting advance orders from subscribers and producing excellent, relatively inexpensive and attractive books. Meanwhile fans and serious collectors distinguish between truly original books and what are, at bottom, expensive reprints of trade editions. This was evident last February at the Mark Marlowe sale, the first major public auction of sf books, held in California and watched closely by book dealers and collectors all over the country. Most of the recent limited editions (and Marlowe had them all) went begging, selling for their original price or below it.

More than a few fans have turned to collecting paperback sf primarily. Many of the masterpieces of the field first appeared as paperback originals, from Kurt Vonnegut's The Sirens of Titan (1959) through the early novels of Samuel R. Delany, Roger Zelazny, Ursula K. Le Guin, J.G. Ballard, Michael Moorcock, Gene Wolfe, Gregory Benford, Joanna Russ and a hoard of others. No major collection of sf is significant without a considered selection of paperbacks, and once again the fans are preserving them--although in the decades to come I expect that early paperbacks, like the early pulp magazines, will become the bailiwick of major libraries capable of caring for fragile, degenerating paper.

Academic reassessment and historical scholarship devoted to sf have also changed the nature of collecting. H. Bruce Franklin's innovative study, Future Perfect: American Science Fiction of the Nineteenth Century (1966), demolished the fan prejudice against sf written before 1926 (when Amazing Stories, edited by Hugo Gernsback, appeared). And the first serious bibliographic work on early sf became available over the next 10 years, from I.F. Clarke, Thomas D. Clareson, George Locke, Stuart Teitler, L.W. Currey and Darko Suvin. This deep interest in the roots of sf has led to active collection-building in 19th-century material, most of which is authentically rare, especially the pre-Wellsian space voyages published in England and America. In such a period of original research, unrecognized gems that have gone homeless on a dealer's dusty shelf may suddenly metamorphose into expensive rarities. And a bent for original scholarship can turn a collection from good to great.

If you have read and bought fantasy and science fiction at one time in your life, you have the potential to turn your accumulated books into a valuable collection, even today. Do you love certain authors? Then develop your collection by obtaining each new book they publish and, if you can afford it, by buying their previous first editions. Do certain themes appeal to you? Then check your reference books and collect everything written about robots, or atomic power, or Mars, or social revolution, or books written by women, or by scientists; first books; award winners; award nominees; vampires. . . . The possibilities are infinite and you may invent any category you choose--and the better you define it and complete it, the better and more valuable your collection.

Investors often tend to collect "high-spots," famous works which maintain a high price and are secure investments. But if you give time to your books, read them, plan ahead by obtaining new works as they appear, a small investment in money can grow into a significant and very valuable collection. Trade or sell the books that do not fit your plan. Replace imperfect copies with books in excellent condition whenever you can. Bargains are available at most sf conventions--there are at least 50 a year--and paperbacks are everywhere and still comparatively cheap. Learn how to recognize the material you need and you will be an effective bargain- hunter. And even if you only collect the books you have read and loved, your shelves will possess special and intrinsic meaning to you, regardless of market value.

Science fiction has become deeply embedded in the popular culture of Western civilization, and there are as many people in daily life to admire and envy a bookcase full of Clarke and Asimov, Vonnegut, Wells and Philip K. Dick first editions as there are to covet a case of John Cheever, John Updike, and Bernard Malamud. Indeed, to judge from dealer's prices and the availability of books, there seem to be more avid collectors of Robert A. Heinlein than of Saul Bellow. Thus the sf boom continues. Selected Reference Works

Barron, Neil. Anatomy of Wonder. New York: Bowker. Second edition, 1981. (The best annotated descriptions of sf books from the 18th century to the present.)

Clarke, I.F. The Tale of the Future. London: The Library Association. Third edition, 1978. (A fairly comprehensive checklist of works set in the future.)

Currey, L.W. Science Fiction and Fantasy Authors: A Bibliography of First Printings of Their Fiction. Boston: G.K. Hall. 1979. (The standard work, comprehensive and authoritative, on modern authors.)