They say that"s a slight drop on last year"s figure of €562.
At the height of the boom, people typically blew €1,400 over the festive period.
But despite the reduction in spending, the survey also shows many people still struggle to cover the cost of Christmas.
On average, it takes two months to recover from overspending during the holidays.
Less than half of those surveyed can rely on their regular income to pay for Christmas - four out of ten will dip into their savings; and 14% will borrow money through credit cards, credit union loans, family and friends or moneylenders.
Mandy Johnson of the Irish League of Credit Unions says there are some positives to be taken from the survey: