The Riverdale Bookshop, one of a diminishing number of used book stores in the area -- and one that has barely raised prices in nearly 30 years -- is closing at the end of this month.

Hardcover mysteries cost 25 cents each or five for a dollar. Paperbacks run four for 25 cents, nine for 50 cents and 19 for a dollar, and that was before the going-out-of-business sale.

Old-fashioned and time-worn, with books stuck everywhere, the small store at 6104 Rhode Island Ave., has been operated by the Sorrell family for years, and doesn't even have a phone.

Some customers say they have been coming there since they were children.

"This place has been another liberal education for me," said one 22-year customer. "I got one when I went to college and I've gotten another since I've been coming here."

"Because everything's so cheap, I've been able to buy and read things I would never have been able to afford otherwise. Politics, sociology -- things I didn't study at all in college."

One of a handful of used book stores in Prince George's, "it's the only place of its kind" in this area, said Mary Monteith, owner of The Book Nook in College Park. "The crooked floors, the old-timey atmosphere, the fact that the Sorrells haven't changed their pricing policies in so many years ./ ./ ./ ./"

Steven DesRoches, an employe at the Book Cellar in Bethesda, can remember being taken there as a child by his book-seller father "for afternoon after afternoon of endless browsing. There were books in every conceivable nook and cranny and you never knew what you might find in one you missed the last time. It was a fire department's nightmare, but a book lover's dream."

Throughout the store, random piles of chronologically arranged National Geographics lean precariously over biographies, and works of poetry and religion. Antique lanterns and wrought-iron light fixtures hang from a wire strung along the ceiling and an old-fashioned telephone is attached to the wall just around the corner from the Love and Lust section.

"We have been considerably inspired in our own business by the Riverdale," said Carl Sickles, owner of the Book Alcoves in Rockville and Gaithersburg. "The prices at the Riverdale have always been so reasonable that I think they have allowed a lot of people to read things they ordinarily would not have."

The Riverdale shop was started in 1956 by Arthur C. Sorrell and a partner, who left 10 years later after a fire to start the Old Hickory Bookshop in Brinklow, in northeast Montgomery County. Sorrell moved the store to Rhode Island Avenue.

Sorrell died in 1971 and the shop is today owned by his wife, Mary, and run by their children, Michael and Claire.

Among the clientele are book scouts and dealers, and scientists and a retired snake keeper, who came for the science books, Michael Sorrell said.

Half his customers come from the Riverdale area and the rest from elsewhere in the area, he noted. "Book people," he said, "think nothing of traveling 20 or 30 miles."

Sorrell said that while he has been looking without success for a place to move, and still hasn't decided if he will relocate. He's closing because his landlord, a plumbing company next door, is expanding and needs the space. Sorrell says he has no hard feelings. "Sometimes people don't understand that this is a business too," he says. "They tend to view it as an institution.