This is a textbook definition of misplaced priorities: a Manhattan school purportedly too poor to buy textbooks spent thousands to send staffers on a California junket — complete with a party at Disneyland.

Life Sciences Secondary School, where Principal Kim Swanson dumped “outdated” student textbooks, shelled out at least $15,000 in taxpayer dough to send herself and eight staffers to a March academic conference in Anaheim.

The school paid for airfare, hotel rooms and registration fees for the three-day affair, which included a gala event at the Magic Kingdom, according to a memo obtained by The Post.

“It was essentially a weekend away in California on the city taxpayers,” said one educator, who didn’t attend.

The pricey trip came to light after The Post’s front-page revelation last week that Swanson was disposing of the school’s books.

Attendees of the Association of Supervision and Curriculum Development’s national conference were all invited to a “breathtaking extravaganza” put on by Disney.

The fancy Saturday night event included animated films, music and laser effects. Life Sciences staffers were given Friday, March 24 and Monday the 27th off to attend the conference.

The trip occurred while the Upper East Side school’s administrators got rid of hundreds of books, which piled up in overflowing stacks on the first floor, saying they preferred modern technology instead.

Among the discards: textbooks on literature, Latin, algebra, geometry and the sciences — including many copies of the expensive college-level “Campbell Biology” which goes for $150 new — plus Regents and SAT study guides.

“What type of message does letting them sit there send to kids — that books are useless and unimportant?” a teacher asked.

A day after The Post revealed the purge, all the books were returned to a locked storage closet.

In a meeting, Swanson told teachers, “We can go down to see if there’s anything we want . . . If anybody needs a book we can talk about it,” according to one who was present.

Swanson told faculty that textbooks could be used in class, but the school could not afford to buy enough new ones for all kids to take home. “According to her, there is no budget for that,” a teacher said.

Teachers said they relied on photocopied materials, and were discouraged from using books.

A city Department of Education spokesman said the 616-student middle-high school “has purchased new textbooks throughout the year,” including 36 Common Core Algebra 1 textbooks delivered last week.

The DOE spokesman would not comment on the cost of the California trip. Swanson did not return a message.