Joshua Thomas had been using his Opal card for almost a week before he realised just how much he was saving.
Mr Thomas works at UTS in Sydney and catches the train between Albion Park and Central five times a week.
It was only after a work colleague said he might "save a couple of bucks a week" that Mr Thomas signed on.
"I was obviously cautious at the start," Mr Thomas.
"Everyone had hyped it up as being such a bad thing. I was reasonably cautious but decided that it was going to happen anyway so I figured I'd jump on board.
"After only a week of using it and realising how much money I was going to save, it's been a no-brainer."
Mr Thomas worked out his Opal card saves him at least $15 a week - more than $700 a year.
His saving comes from catching off-peak trains in the morning and afternoon. Taking an off-peak train from the Illawarra to the Sydney CBD costs $5.67 on Opal, as opposed to an $8.10 regular fare.
It's highly likely the majority of commuters to Sydney would travel during the off peak - most likely in the early morning.
So Mr Thomas said it's not hard for daily commuters to save.
"If you can get even one of your journeys at the off-peak rate you're saving quite a lot of money," he said.
"You're going to save half of what I'm saving, so 7 or 8 bucks a week, which starts to be a huge amount over a year."
One of the key Opal selling points is free travel once eight journeys in a week have been made.
Despite living in Albion Park, Mr Thomas said being able to travel free has made him more likely to catch the train to Sydney on the weekend.
"A train ticket to Sydney is not very cheap but knowing I can get on for free is always a consideration to go," he said.
"If I'm going to pay $11 for my return and $11 for my wife return, maybe we'd drive to Sutherland and catch the train from there. But it became a no-brainer because if I'm free, we're only paying for one journey somewhere over the weekend.
"Also, with overtime shifts, picking up Saturday and Sunday work, knowing it's not going to cost me any more money to get here is definitely a consideration in going."
The Opal card system has seen a few glitches, most notable have been the reader failures at some Sydney stations where commuters are stuck behind the barriers waiting for the readers to reboot.
Mr Thomas said he's never seen anything like this.
As well as the money he's saving, Mr Thomas also identified the convenience of the card as major appeal.
Once a week, his wife just transfers money over to his Opal card while paying other bills and he enjoys the result of that all week long.
"I find it easier - I don't have to get to the station earlier on Monday morning to line up with the masses and get a weekly ticket," he said.
"That can get a bit tedious lining up with 30 other people trying to get a ticket five minutes before the train."