Flying a special adviser to North America cost the Department of Education almost 50 per cent more than travel for the minister, the Irish News can reveal.
John O'Dowd, his adviser and senior department officials took a five day trip to New York and Toronto in 2013.
While it cost the department about £3,000 to send the minister, the bill for his `spad' topped £4,500.
Overseas travel paid for by education authorities has been in the spotlight with details of massive costs emerging at a time when schools face savage cuts.
The Irish News last week revealed that cash-strapped boards spent almost a quarter of a million pounds on foreign travel. The United Arab Emirates, Ethiopia and US were among 21 different countries across four continents visited in a four-year period.
Savings of almost £200 million must be made across the education system in 2015/16. Casualties of cuts so far include language classes for primary pupils, a free book scheme for children, and school maintenance work.
The minister's 2013 trip cost slightly less than £14,000. The total cost for his spad was £4,536 compared to £3,079 for the minister. An additional £6,070 was spent on departmental officials who also travelled. It is, so far, the only trip taken by the minister outside the UK and Ireland.
At the time, Mr O'Dowd said New York and Toronto both had "much to teach us about improving educational attainment".
In the international PISA results, Canadian 15-year old pupils outperformed their counterparts from the north in reading, maths and science. Mr O'Dowd said he also noted Ontario's success in breaking the link between socio-economic background and educational attainment.
In New York, the delegation visited numerous education projects in the city to see how schools were engaging parents and communities in children's learning.
The department has not yet explained the reason for the difference in the minister and his adviser's costs.
Justin McCamphill, the NASUWT's national official for Northern Ireland, said the North America trip was a good idea but added that education authorities needed to be careful when making spending decisions.
"It is good that the minister is wanting to find out how other education systems tackle inequality. We need to learn from good practice in other jurisdictions," Mr McCamphill said.
"I would still urge that spending be kept to the front-line and that there should be wider use of technologies such as video-conferencing."
The Education Authority, which replaced the five area boards in April, has defended the amounts spent on travel.
"International experiences enable educators, formal and non-formal, to move young people into environments where identity, nationality, and religion are not necessarily seen as issues that cause division. They also give young people new insights into important social issues like poverty or immigration," a spokeswoman said.
"By providing these types of opportunities for engaging with others from a range of backgrounds in different settings, we create space and time for educators and young people to reflect on their own assumptions and understandings."
