SALT LAKE CITY — It's a book collector's dream: rifling through the shelves of a secondhand store and finding a valuable text for a bargain price.

It happened Jan. 31 to a man who plunked down $40 and took home eight books of sermons and writings from elders of a secretive and polygamous Mormon breakaway group, the Fundamentalist Church of Jesus Christ of Latter Day Saints.

Adding interest to the find — the books are inked in red with a property stamp from Purgatory Correctional Facility, the jail in Hurricane where FLDS President Warren Jeffs is awaiting trial on charges of rape by accomplice.

The volumes are rare and likely worth much more than the purchaser paid, say booksellers who trade in early writings from leaders of the mainstream Church of Jesus Christ of Latter-day Saints. It's still a mystery how the books made their way to the thrift store.

"Those books are unbelievably scarce," said Tom Kimball, a collector and seller. "They could be worth thousands. It's every Mormon book nerd's fantasy."

Members of the FLDS live intensely private lives and shun most interaction with outsiders, including members of their own families who leave the faith. For decades, members have lived in the remote twins towns of Hildale, Utah, and Colorado City, Ariz., dressing in 19th century-style clothes, rejecting the trappings of modernity and striving for perfect obedience to God.

Drawing on the early theology of the Mormon church, the sect continues to practice polygamy, believing that plural marriage brings exaltation in heaven. They consider Jeffs a prophet who communicates with God.

While some fundamentalist works are available, the nature of the various polygamous groups usually means printed materials circulate only internally, said Ken Sanders, owner of a rare-books store in Salt Lake City.

"It's very, very rare," said Stan Larson, curator of manuscripts at the University of Utah's Marriott Library. "We would be very glad to have them."

The volumes were produced between 1994 and 2006 by the Twin City Courier Press, of Hildale, a company owned and operated by a member of the fundamentalist church.

Each of the 8 1/2-by-11-inch books is hard-bound in a black cover with its title printed in gold leaf. Depending on the volume, publishing credits are either awarded to Jeffs or his predecessor and father, Rulon Jeffs.

Six of the books are the collected sermons of former FLDS President Leroy S. Johnson, who led the fundamentalist church from 1955 until his death at age 98 on Nov. 25, 1986. The sermons begin in 1950, and each reflects the occasion or location where it was delivered, including the southern Utah communities originally called Short Creek, Salt Lake City and a small FLDS enclave in Canada.

Some of the writings appear to be from Johnson's own hand, imparting his personal stories, reflections or anecdotes. Others draw primarily on scriptural references from either the Bible or the Book of Mormon and cite sermons or speeches from early leaders including Joseph Smith, Brigham Young and John Taylor.

Two of the books are collections of "Zion's Light Shining," a monthly FLDS newsletter that originated with Rulon Jeffs, who assumed leadership of the church in the 1980s. The newsletters, each about 40 pages, date to February 1999 and contain similar material, along with writings from various FLDS elders.

"With Every Breath, Keep Sweet, No Matter What" and "Perfect Obedience Produces Perfect Faith," the newsletter masthead reads, reinforcing two key tenets of FLDS faith.

Ben Bistline, a former FLDS church member and a historian who has written two books about the FLDS, said the volumes are likely reprints of books first published about 1980. Then the collected works of Johnson were churned out in paperback for church members' personal use.

"But you had to get permission of the prophet to buy one," recalled Bistline, of Cane Beds, Ariz. "They published the books to promote polygamy and their way of thinking."

Bistline questions whether the volumes are a complete record. If memory serves, he said, FLDS leaders selected the teachings they thought would be most useful to members.

Although some of the writings tout the practice of plural marriage and others warn of government persecution from the states of Utah and Arizona, there's not much fire and brimstone.

The collector, a fundamentalist from St. George, in southwestern Utah, who spoke only on condition that his name not be used, said he bought the volumes because of his interest in early Mormonism and because of his own beliefs. He let a reporter and a photographer from The Associated Press look at the books, but said he had no immediate interest in selling or donating the books.

"An interesting find for me," he wrote in an e-mail about the books.

It's unclear when or how the books made their way to the jail, said Washington County sheriff's Lt. Jake Adams.

Jeffs, 51, is charged with two felony counts of rape as an accomplice for having forced a religious marriage between a 14-year-old follower and her 19-year-old cousin in 2001. His trial is scheduled for this September, roughly a year since he was first jailed.