"Can't say I expected this," Ardern posted on social media after what she described as her "faux pas with the old mic in parliament" raised the sum for New Zealand's Prostate Cancer Foundation.
A microphone picked up New Zealand's premier muttering the insult, aimed at political opponent David Seymour, following a heated exchange between the pair during a parliamentary session last week.
An exasperated Ardern was overheard saying "he's such an arrogant prick" as she retook her seat after answering a barbed question from Seymour, leader of the right-liberalist party ACT.
Seymour petitioned the speaker of New Zealand's parliament to get an apology from Ardern, which meant her comment was entered into the official record, known as the Hansard.
Seymour came up with the idea of joining forces for a good cause and they both signed a copy of the transcript which was framed before being auctioned.
"The interest was greater than anyone dreamed," Seymour said in a statement, after having told AFP he had only expected the transcript to reach a fraction of the winning bid of NZ$100,100 ($63,200).
Ardern also "thanked everyone who placed a bid" and praised Seymour for being "a good sport", a compliment the ACT leader reciprocated.
"When I suggested this to her, she immediately agreed," Seymour said.
"I have been blown away by the kindness of bidders who are helping pricks everywhere with their generosity," he added.