The tribunal found a contract had been formed when the homeowner accepted the painter's quote issued prior to work being carried out.
And while the tribunal was concerned with the enforcement of contracts and not with interfering with them, there were some exceptions.
"It is not for this tribunal to rescue people from possibly bad bargains they may have entered into, including the price charged for the provision of services," the decision said.
However, it could vary the relative agreement of the contract if it was found to be "harsh or unconscionable".
The tribunal considered there to be a relatively high bar to reach by a party challenging an agreed term as to price as being hard and unconscionable.
However, following the hearing the adjudicator deemed the painter's quote met this threshold after other quotes sought by the house owner for the same work ranged between $3723 and $6210 and an average of $4710.
While the house owner had sought quotes from people who visited the property, the painter provided estimates ranging from $11,771 and $13,961 from painters who had not.
The figures placed before the tribunal by the customer were "more genuinely indicative" of the market range for that type of job, according to the decision.
The home owner's quotes had been for a base coat and three top coats, which was one less coat than the four applied by the painter.
The tribunal said based on what they had heard, three coats would have been adequate.
The tribunal agreed with the home owner that the difference of $10,000 between her highest quote and the applicant's quote was so great as to be "untenable and unsustainable" and so far outside the range of what could possibly be reasonable as to be, in short, outrageous.