Women filled nearly every seat in the public gallery as Justice Venning revealed details of the man's "harrowing" offending against two girls and close friends, aged 14 and 15.
The man was aged 35 when he began his offending in December 2019. The offending lasted until February 2020.
He first met the 15-year-old after being introduced by a family member. He garnered their trust as the girl's parents believed he was helping her with personal issues.
The man was invited to move into the family home, where he spent more time with the teenager, eventually sleeping in the same room as her.
Justice Venning said the man began having sex with the girl, at times waiting until her parents were asleep. There were times the man would have sex with the victim while she slept, he said.
A 14-year-old friend of the victim stayed over one night, during which she awoke and was forced by the man into having intercourse with him.
From there, the situation spiralled when he told the girl he wanted her to have sex with other men.
On January 31, the man placed an advertisement on a website called Locanto seeking "an older gent to have sex with young girlfriend; rewards or cash could help" along with a photo of the teenager.
Nine men responded to the ad, with four of them arranging to meet and have sex with the victim in exchange for cash, with discussed sums ranging from $100 to $200.
One failed arrangement involved a man offering payment for sex with the girl of $100 and a fishing rod and reel.
Marcus Barker, 55, Owen Sigley, 66, Auckland church leader Michael Weitenberg, 54, and Calvin Fairburn, 37, were sentenced to home detention for their part in the underage sex ring that saw them pay for sex with the 15-year-old.
The man's offending emerged on February 17 when he was confronted about his actions - a day after he and the girl had sex in a classroom at her school while her brothers played.
Justice Venning said four victim impact statements provided by the girls and their families made "harrowing" reading.
"It's difficult to imagine how the principal victim will recover from the abuse at your hands in her home where she should've been safe," Justice Venning told the man, who looked back impassively.
He said the older victim was vulnerable and there had been a planned abuse of the trust she and her family had in the man.
Instead, Justice Venning said, there had been a cynical and abusive commercial gain as the man had treated the girl's body like a commodity to be sold.
During sentencing, Justice Venning accounted for their significant age difference, the abusive character of the relationship and the severe breach of trust.
No discount was given for remorse, as Justice Venning said the man 's statements failed to show any true remorse for his offending.
Discounts were given for the offender's early guilty plea and for his lack of connection with his family from Ngā Tahu and Aboriginal heritage.
The man received seven years and 10 months' imprisonment for the charge of dealing in a person under 18 for sex.
He was sentenced to five years in jail, to be served concurrently, for four counts of dealing in a young person for sexual exploitation, and seven counts of dealing in a young person for commercial sexual services.
Eight charges of unlawful sexual connection with a young person and one charge of indecently assaulting a female under 16 saw him sentenced to four years and three months' imprisonment, to be served concurrently.
