AIUI since 2015 Galway ceased commercial operations at Carnmore and there is no longer any controlled airspace in that area. Inishmore just need 3 hrs prior notice.
Last time I visited. there was no one there and the landing fee was a donation to the lifeboat collecting box. Things may have changed since.
An abbreviated flight plan to enter controlled airspace VFR can usually be done over the radio, but unless you're routing through Shannon or other main airport airspace, it shouldn't be an issue.
There is an online VFR chart
here