If a name error is a single letter in the middle of the name and you dont pass any comment as to the error on check in in it won,t even be noticed. Use you booking reference to check in at the self service kiosks.
If the spelling error changes how the name sounds/looks ie first letter then bite the bullet, curse yourself for not being able to spell your own name correctly and pay the money. Aer Lingus wil offload you at the gate if you try to pull a fast one and go directly to the gate and then charge you a fare difference and reservations change fee and your name change fee.
You are advised as part of the booking process that the name on the reservation must match what the form of id is being presented at the boarding gate so all you John's who like to be called Billy Bob by your friends remind them of your correct name if they are booking your flight tickets for you or you will have to pay.
Finally, remember that in the old days you could not change the name on a ticket at all. So the ticket that cost 3/4/5/10 times as much was worthless and non refundable.