"More defendants are to come, and the court needs to set a benchmark. The appropriate benchmark is imprisonment," Smith said.
Barker's lawyer Jonathan Natusch, however, said jail would mean the end of a cleaning contracting business he had built up over 20 years, and the likely loss of the home he shared with his son, who he had brought up as a solo parent since the boy was three years old.
Natusch said Barker had cooperated with the police, handing over his passwords and electronic devices immediately, and was prepared to act as a witness against the victim's boyfriend – potentially sparing her the trauma of a trial.
After the charges were laid Barker had gone to a number of people in the Kaitaia community to explain what he had done.
"He has seen his standing fall dramatically, and that is a source of distress to him, in the eyes of everyone he knows."
Judge Deidre Orchard took three years' jail as a starting point for the underage sex charge, and added a year for contracting sexual services with an underage person.
She then reduced the term for his early guilty plea, previously unblemished character, cooperation with police, and his willingness to testify against his co-offender.
That resulted in a term of two years' jail, making him eligible for a sentence of home detention instead.
"Not only did you cooperate with police from the beginning, you made a formal statement against the young man who was effectively prostituting his girlfriend … that may well end in a plea of guilty, which will spare the complainant the ordeal of court."
Barker was sentenced to 12 months' home detention and ordered to pay $1000 reparation to the victim for emotional harm.
Judge Orchard said the outcome for Barker's type of offending was almost always prison because of the need for deterrence.
However, she had been impressed by Barker's previous good character and dedication to his son, things she rarely saw as a judge.
"There is an exception to every rule, you deserve to be the exception."
However, Barker's sentence should not be seen as a precedent for the other defendants awaiting sentence, she warned.
A spokesman for Stop Demand, Mike Shaw of Kaikohe, was present in court.
He said the sentence was a "terrible precedent" and "a joke".
A 15-year-old was still a child and could not legally consent to sex, he said.
Another hearing will be held on October 2 to decide whether Barker should be placed on the sex offenders' register.
