etap - nearer to alea but not far from merrion either
Going on previous etap experience if you want really cheap and no frills whatsoever then this place would suffice.
It's literally a place to sleep and shower with no comforts whatsoever but it is undoubtedly cheap.
Park Plaza is pretty cool and not too expensive at all. They did late checkout of 6pm for a tenner as well which was brilliant and almost essential after a big night on the beer with Mr Hopkin.