In May we stayed three nights at Harvey's Guest House which is an 18 minute walk from EPIC. Remodeled older building, but unless you plan to be in your room all the time, just fine. That was found on Booking.com so maybe it's unavailable. $164/nt for double.
A friend always stays "out of town" but right on a regular bus route within 30 minutes of town. Again, unless you plan to spend lots of time in the room, not a bad choice.
The Dublin council banned unlicensed short-stay accommodations like VRBO in late 2019 to help with the housing shortage, and the prices shot up. Then Covid. Ireland is the most expensive vacation spot in the EU, according to the EU's statisticians. We've spent a few days during each of our first three trips to IE, and now do our planning to avoid Dublin stays. We just go to/from DUB to Belfast, Glendalough and the like.