Scalpers are demanding up to $550 a ticket for tomorrow's Big Day Out event on the internet.
Organisers are warning concertgoers not to buy the tickets from the racketeers as they could lead to them being refused entry to the event itself.
The 40,000 tickets for tomorrow's event at Mt Smart Stadium sold out in record time and organisers had to sell another 2000 on Monday.
But ticket scalpers, sensing a chance for a fast buck, were quick to move on the opportunity and the hundreds of tickets advertised on Trade Me last night were being sold at prices well above their initial $110 cost.
One punter wanted $550 - five times the face value - for a single ticket to the show.
Big Day Out promoter Campbell Smith said there were means of identifying tickets which had been scalped and concertgoers who presented these could be ejected from the event.
"We could do because the tickets can't be transferred and we can tell which ones have been sold on because some of the photos on Trade Me have the ticket numbers," said Mr Smith.
"But our position on it is that this would just punish the average punter and we've got better things to do than that."
Mr Smith said he supported proposed legislation to prevent ticket scalpers from profiting on sporting or music events and Economic Development Minister Trevor Mallard's Major Events Management Bill, will outlaw the sale of tickets to a major event for more than the original sale price.
Mr Mallard said in 2005 the proposal applied mainly to sporting events such as the 2011 Rugby World Cup and the 2015 Cricket World Cup, but legislators would consider other definitions of "major events" not linked to sports.
Mr Smith said this year's Big Day Out, which featured The Killers, My Chemical Romance and Tool among many other acts, was "possibly our strongest line-up yet which has probably led to this sort of activity".