just to jump in, I don't know what AerLingus is like, but I do know what Dublin and Ireland in general is like.. from 54k a year you will pay just short of 1/3 in tax which is fairly standard across EU. Ireland has a progressive tax system, so small and middle income earners pay less tax. As for the accommodation - yep, it is expensive and I doubt you will find anything decent for 1k in Dublin.. However, especially if you have a car, you have no good reason to live in Dublin, there are loads of commuter towns surrounding Dublin airport where you can get a decent 3 bed house for 1k or a 2 bed apartment for less
taking that into account, the average salary in Ireland is about 45k, so really with 54k one should expect to be doing alright