Taylor Swift is set to register one of the highest-grossing tours of all time according to sources responding to claims that sales for Reputation have been sluggish.

A music industry insider earlier this week told the New York Post newspaper that sales have been a “mega disappointment” since opening in mid-December. None of the 33 North American shows have sold out yet.

However, a source close to Swift told Billboard that the tour could generate sales worth around $450m (£330m/€375m), which would make it one of the highest-grossing schedules ever.

Billboard said each show on the tour is forecast to sell between $7.5m and $10m worth of tickets. With Swift’s team confident about sales, which they claim have been slower than her 2015 tour because of the employment of Ticketmaster’s Verified Fan technology, eight more North American shows are likely to be announced.

With 41 shows in North America, six in Europe and five in Australia and New Zealand, Swift would be looking at earning anywhere between $390m and $510m for the Reputation tour.

U2’s 360 tour of 2009-11 is the highest-grossing tour of all time having generated $736m, according to Billboard figures. Swift’s Reputation schedule would sit comfortably in the top 10 if it does break $450m.

Patrick Ryan, co-founder of ticketing and distribution company Eventellect, told Billboard that while he backs artists and ticket vendors looking to take on scalpers, he is concerned that the increase in ticket prices for Swift’s tour could have a negative effect on event sales.

“Whenever I see an upper deck ticket priced above $200 for a football stadium tour I have a hard time imagining that fan will leave the show thinking they got their money’s worth,” said Ryan. “Regardless of whether they bought that ticket on the primary or secondary market, $200 is a lot to spend on a seat literally in the rafters.”

“Overall, it’s good and smart for Taylor to price her tickets higher, but it could cannibalise other games or shows, because for most consumers, they don’t have an endless budget.”