Phones in Ireland

You can buy a phone and service, at worst, at a mobile store. Here are some you might be able to buy at a Vodafone store for example:

http://shop.vodafone.ie/shop/pay-as-you-go-phones

You can see there that some of the cheap flip phones are only about 30 euros.

Here is some info about other mobile carriers in Ireland:

http://prepaid-data-sim-card.wikia.com/wiki/Ireland

If you want a decent Android (5" screen), my unlocked Moto E4 can be bought now for $100 from B&H - it will work on any North American carrier as well as any in Europe. I used mine in Portugal in May. I had LTE sometimes, 3G at others.

https://www.bhphotovideo.com/c/product/1342874-REG/moto_01154nartl_moto_e_16gb_fine.html

Not saying this is your best deal, only that it's a pretty decent phone for the money - my every-day phone at home. Biggest downside: not a great camera, just a tad slow.

I am interested in this as well. I will be traveling with a group of 6 family members. I would like to have one working phone to call extended family within Ireland as needed. I heard that a hot spot might be useful as well. I could use it instead of the rented GPS from the car company.

If you need a GPS for driving, any smart phone (and some tablets) will work as a GPS without any mobile service - no SIM card, no hotspot, no nothing. All you need is to download the map "offline" into an app like Google Maps. Try it at home first - download the map for your local area while on WiFi, put your phone in airplane mode, then go for a drive and try navigating with the phone. It will work the same way in Ireland. Download the "offline" area for the part of Ireland you will be driving in within a month of arriving there; Google Maps "offline" maps expire within 30 days and must be re-loaded after that.

A mobile hotspot might make sense if six people have phones and tablets and want to share it - but of course, it works only if all six people are within range of the hotspot. For one person with one phone who needs service, a mobile hotspot is much too expense and would make sense vs. buying a SIM card only if your phone is locked and your home mobile provider doesn't offer a cheap international roaming plan.

You can also use services like Skype and Google Hangouts while on WiFi to make voice calls to phone numbers for a few cents per minute. Hangouts in addition lets you make free calls to US numbers, even landlines, with no mobile service other than being on WiFi.

I don’t know if this is helpful but I have a Samsung Galaxy with Verizon as my provider. When I went to Ireland last year, I was able to pay a daily rate of $10 and have the same coverage I get at home. I did not have to purchase a SIM card or ‘unlock’ my phone. And my phone worked all over Ireland.
Good luck! Enjoy Ireland!!!

Yes, Kelly, the $10/day international roaming plans available from Verizon and AT&T are convenient and work well for many people. The only real problem with them is the cost. The biggest (perhaps only) reason to buy a SIM card is to save money. If you're going on a month-long trip, the $10/day plan would cost $300; you can get a SIM card that may last you the whole month for about 10% of that cost. But for some people, buying a SIM card may be slightly intimidating and not worth dealing with just to save some money. It's an individual preference.