Rumor had it Adele's two Xcel Energy Center concerts would be the hottest ticket of next summer, but even arena representatives were surprised by the demand Thursday morning.

"The amount of fans at the arena blows every prior show out of the water," Xcel Center representative Jora Bart said of the turnout at the X, where she helped 549 people with numbered lottery wristbands line up.

Tickets to the July 5-6 shows sold out online within minutes. It didn't take long for hundreds of them to pop up on resale sites such as StubHub, for $450 on up to the doesn't-hurt-to-ask $9,000.

A ticket-resale professional who was on site at the Xcel box office said he expects seats — priced originally at $39.45 to $147 — to sell for five times their face value.

Which means: People may have to pay scalpers more than $750 for good seats, and about $250 just to get into the building.

"I'm still shaking, I'm so excited," said Cindy Stoewer of Minneapolis, who nabbed two tickets to both nights at the Xcel box office. "I don't think I'd have gotten any if I had tried online."

Indeed, most fans who tried to buy through TicketMaster's website clicked and waited — then clicked again — to no avail.

"I typed anti-bot phrases a dozen times at least, [and] it kept saying it was incorrect, try again," recounted Claire Kirch of Duluth.

Plenty of people who showed up in person also came up short. Gayle Smith of Inver Grove Heights was about 400th in line and had already invited friends from California and Colorado to visit for the show. She said she would likely call off those plans rather than pay exorbitant prices through ticket resale websites.

"They really need to find a way to control scalpers," Smith said. "All it does is hurt the fans."

Adele's promoter, Jam Productions, did implement a rare "credit-card entry" rule for a few thousand of the best seats. That means concertgoers can't gain admission unless they bring the credit card used to purchase the ticket — which curbs scalping, but also can be a hindrance to legitimate fans.

Until 2007, it was illegal in Minnesota to sell tickets for more than face value. Since the law changed, companies such as Ticket King — based in nearby Hudson, Wis., before the scalping ban was repealed — have since opened offices in the Twin Cities. National ticket sites such as StubHub and Vivid Seats have also emerged and made it easier for individual scalpers to sell seats.

Smith remembered walking into Ticket King to try to buy an affordable seat to last year's Justin Timberlake concert at the X. "They laughed me out of the place," she said.

"It is what it is, but there's no point getting too worked up about it," said Nancy Davis-Ortiz of Minneapolis, who was also too far back in the Xcel Center line. "I can always try to win them from a radio station."

The ticket broker who observed the crush Thursday drew a distinction between these shows and the last hot ticket at Xcel in September.

"This isn't mom and dad buying tickets to Taylor Swift for their daughters," he said. "This is mom and dad buying tickets for themselves."

The St. Paul shows kick off a 56-date North American tour by the British hitmaker, who has the biggest album of 2015. Since its release Nov. 20, her record "25" has already sold 5 million copies in North America and spawned the No. 1 single "Hello."

It's possible Adele might add a third St. Paul concert. Her tour itinerary has open dates after July 6, but the singer suffered vocal problems on her last tour four years ago and has been skittish about overextending her schedule. Her last trek, which came to the X in 2011, saw postponements due to a strained voice.