Data from lender Halifax showed that in June this year the average monthly cost of a three-bedroom home for these buyers was around £666 compared with £722 for renting the same type of property - a monthly difference of about £56.
Recent years have seen mortgage rates falling, cutting monthly costs for first-time buyers at a time when rents have been rising.
But the gap over the last year has narrowed amid house price rises.
In June 2009, the average cost of buying was £1,154 higher per year than renting.
Since then, the average price paid by first-time buyers for a three-bedroom house has risen by 25%. But monthly costs have come down as the average mortgage rate has fallen from 4.92% to 2.91%.
Average rents have risen by 23% in the same period, Halifax said.
In June 2014, monthly costs for first-time buyers were £1,018 cheaper per year - or £85 a month - than for those renting. Both have since risen but the 8% rise in the value of a typical home means the gap has now shrunk.
Monthly mortgage costs have gone up by £40 over the year though rents have risen by just £8, the figures showed.
In London, first-time buyers save £973 a year compared with renting but in one region, the South East, renting is the cheaper option by £98 - largely because of house price rises.
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