Today, at 7pm New York time, the most expensive book ever will be auctioned off at Sotheby’s. The 1640 text is a rare translation of biblical Psalms, the Bay Psalm Book. It’s the first English language book ever printed in North America and is expected to fetch between $15-$30 million. From an initial printing of 1,700, there are eleven surviving copies.

Sotheby's Page from the Bay Psalm Book

The two previous sales of the the Bay Psalm Book were the most expensive book sale at the time. In 1879, when rail magnate Cornelius Vanderbilt paid $1,200 for a copy and broke records for book auctions in the US. Then in 1947, book collector Abraham Rosenbach bought the last copy of the Bay Psalm book sold for $151,000 on behalf of Yale University.

Rare book and Americana expert William Reese told Quartz that the text attracts such high bids because of its unique historical importance. Each copy is a relic of the very first print run in the new world as well as a testament to the mindset of early Protestant settlers. The Puritans were conservative religious rebels who’d left the English church they found too decadent. They required a new psalm book, one that was closer to the original Hebrew text, and in verse, for singing.

The copy that is up for sale has been owned by the Old South Church in Boston (one of two in its care) since at least the 1840s. After much debate, the congregation voted in December of last year to sell one of the books to pay for work on the church building.

The sale has attracted uncharacteristic attention to the world of rare book collection. In recent years, online book sales have done some flattening to the rare book market, broadening availability and lowering prices, says Susan Benne, executive director of the Antiquarian Booksellers’ Association of America. She also told Quartz that the rise of e-books has pushed collectors to snap up first editions of newly published books, which have smaller print runs, making those first editions rarer.

This Bay Psalm Book will almost certainly be joining an individual, rather than institutional collection. “Every time one of these books has gone up for sale, the buyer has come out of left field—has not been someone anyone expected to be in rare books,” says Reese. For an institution, it doesn’t make sense to purchase outright an historic publication that it can visit instead. Record-breaking bids usually come from individual collectors, though they may later donate the pieces to universities or museums. Some of the most expensive past book and manuscript sales, like the $11.5 million edition of John Audubon’s The Birds of America and the $21.3 million Magna Carta were purchased by private buyers, in 2010 and 2007, respectively.