Tickets costing up to $153 to the two Auckland shows - on October 13 and 14 at the Vector Arena - sold out within a frantic 20 minutes yesterday.
Within hours, they began appearing on auction websites, with bids reaching $9000.
That sparked anger among those who missed out, with sellers having to defend their decisions and the legitimacy of their tickets.
One, who said he was forced to sell two tickets after friends pulled out, was trashed in the comments section of his auction.
One disgruntled online auction user said: "Curse on you, scalper. Hope they cancel your tickets."
"Others tried to ruin auctions by making false bids. Just after 7pm, someone had bid $25,000 for the two tickets.
"Another wrote: "I will give you $20 million now. Thanks."
On another site, where a general admission ticket was being sold, the latest bid was $50,000.
A Ticketmaster worker last night said the call centre was still being swamped by fans who missed out in the original sale.
Metallica last performed in New Zealand at the Big Day Out in 2004.
