The Pratt-signed copy likely fetched a significantly higher price than unsigned copies have in the past decade because of its provenance, but public sale prices have increased dramatically during that time. For example:

• Sotheby's auction house sold a first edition Book of Mormon for $32,200 in 1997. At the time, a Sotheby's spokesman said the bidding "certainly far exceeded our expectations. It was by far a world auction record for that book," which was projected to sell for between $7,000 and $10,000.

• Hajicek paid $58,000 for a copy in 1999 during an auction at the Western Historical Artifacts and Paper Money Show in Salt Lake City.

• An unnamed buyer purchased a first edition at a West Virginia estate auction in 2000 for $44,000, a price one rare document dealer at the time termed "a steal."

The hymnal, titled "A Collection of Sacred Hymns, for the Church of Jesus Christ of Latter-day Saints," was compiled by Smith's wife, Emma, and was published in Nauvoo, Ill., in 1841. A press release announcing the sale said the rare first edition "has not appeared at auction in the last 100 years."

Hajicek said the first edition hymnal was printed in 1835, and the auctioned book was a second edition that is "still very rare, probably more so than anyone thought." He said collectors are interested in it because of Section 25 of the faith's scripture, Doctrine and Covenants, "essentially classifies this as a sacred book equivalent to scripture. Because the second edition has more hymns than the first edition, that makes it in some sense the first printing of some scripture."

He said the hymnal that sold "was a $12,000 book in 1993 — now it's at $180,000. That tells you a lot." After collecting for 25 years, Hajicek said he has his own large hymn book collection, and there are "a dozen important ones" now in circulation among collectors.

Chris Jones, a buyer's representative, was at the Swann auction Thursday and bid $120,000 for the Book of Mormon, "but it went to $150,000 real fast." He spent all day Wednesday examining the collection, with particular interest in the Mormon documents. He said the book "was in very nice condition. It needs a little leather work," but "the history of the book is wonderful."

The price on the hymnal "surprised us all. I went up to $80,000 on that, but they went by that awful fast. It was in wonderful shape, and the same size as the 1835 edition that Emma (Smith) published in Kirtland. 'A real sweet book' is the way I'd describe it."