Irish Rail ticket strategy

Irish Rail have 3 tiers of on line pricing-
Low- Amend or cancel up to 48 hours ahead for a 50% fee
Semi Flexible- Amend or cancel up to 24 hours ahead for a 20% fee
Flexible- Amend or cancel for free up to 1 hour before travel

So if you choose the Flexible Fare on line, if you take off late so have no chance of making it, you can change while on data in the airport, or WiFi in the air, or once you land and are back on data or wifi in the airport you can amend there if needs dictate.

Walk up fares are approx double even the flexible fare for any given journey. Like most trains in Europe they can't sell out but if you walk up and buy you may end up standing- defeating the purpose of this exercise.

There are also direct buses to most points west from the airport- some routes with multiple operators.

Where exactly in the "west" is your destination?

The bus can be another good option (I dare say, maybe even better than the train). The bus is cheap, comfortable, has wifi, is about as good an environment for napping as the train is, has more frequent departures, and it leaves right form the airport - just steps from the airport terminal. We arrived early, grabbed our bags, exited the terminal, walked to the bus (aka "coach") stand, there was a bus sitting there, we walked on, and settled in to the upstairs front bench seat (roomy, comfy, cozy), with panoramic windows and nice views. The drive to Galway was smooth and easy, and we both napped a bit on the way.

With the train you have the extra step (and expense and hassle) of first getting from the airport into central Dublin to the train station. IF your destination is served by bus, I'd skip that extra trip into Dublin, and simply walk on to the next bus. Easy peasey.

Thank you both, but I'm not sure if that really answered my question, so I'll restate. First, we cannot take a car or bus (please take my word for it), so my question is only about rail travel, toward Galway. Second, we may not know if we'll make it on-time to the first train before the 60 minute change window of the flex ticket, due to when we deplane & how busy customs may be. That is, it will likely be less than 60 minutes before the early train's departure when we'll realize we can make it or not. And third, do the Saturday morning trains sell out often that time of year? The 11:25a train has already sold out all low & semi-flex tickets, even though it's 2 months away! Do they add more cars?

Based on that additional information, it seems to me the best strategy is to purchase a ticket for the later train, then change it to the earlier one if we get there in time. But since I'm unfamiliar with Irish rail, I wanted to know whether that makes the most sense & is easily done. For example, if we get there just in time, will it let me make the change to a train that is about to leave, or must I make the change 60 minutes before the earlier train, not just the later one? Thank you.

P.S. We could also just purchase tickets for both trains and discard one, if that helps, but that's rather wasteful.

Sound like you should just buy two flexible fares, and plan to cancel one of them an hour before departure.

Irish Rail trains do not sell out. But certain fare types do. From Dublin to Galway a ticket bought at the station on the day is 29.30 Euro.

If you book on the 1125 that can be amended until 1025. But, and it's a big but once the 0925 is platformed and boarding then you can no longer reserve a seat on it, so by around 0905 you can no longer switch to that train, but can still buy an unreserved ticket for it, in person at the price above, until about 0922 or 0923.

You equally can't amend the 0925 to a later time after 0825.

All trains have unreserved seats, that is not all capacity is pre sold. But unreserved customers may exceed the number of such available seats. Unless something very unusual is happening- like a football or shinty match or a major concert (like Taylor Swift) or the Pope visiting they will not add extra cars.

Thanks so much, those replies answered my questions. I didn't realize I can just cancel tickets, so I think I'll buy 2 tickets, then just cancel the one I don't use. Thank you!