Haines met the victim and a male associate of hers at the Wellington train station, and drove them to his home, where he and the victim engaged in sexual activity while the other man waited in the lounge.
Haines paid the victim $300 and drove them back to the train station.
The other man gave Haines the number of another underage sex worker, who Haines then contacted.
He put $100 into the other man's account and arranged to meet with the second victim.
Before their meeting, she had already told him over text she was only 17.
He met her at Karori Park and drove with her to Makara, where she performed oral sex on him for $50.
Haines refused to make any comment when questioned by police.
Crown prosecutor Michael Blaschke said Haines' explanation ahead of sentencing that he didn't realise the legal age for prostitution was different to the legal age for sex "beggars belief".
He said there was an "absence of remorse".
"There is simply remorse for the situation he has found himself in."
Defence lawyer Paul Knowsley said Haines had experienced a "spectacular fall from grace" and had "much remorse" for what he'd done.
Judge Lance Rowe said the law preventing people under 18 from engaging in commercial sexual activity was there "to protect young people from sexual exploitation and at times protect them from themselves".
In the case of the 14-year-old victim, Haines "took insufficient care that the law requires ... to establish her age".
Judge Rowe said it was difficult to distinguish when remorse came out of self pity or a desire to gain a lighter sentence, and when it was genuine, but he accepted Haines was remorseful and that his reparation offer was the best he could do.
A pre-sentence report assessed Haines as genuine, and said he expressed "disgust" in himself for the position he placed the victims in.
Judge Rowe allowed him discounts on his sentence for his remorse, his efforts to rehabilitate, his contribution to the community, and his guilty pleas.
He sentenced him to six months of home detention and ordered him to pay $500 emotional harm reparation to each victim.
