The Corrib Village is a great economic alternative to booking into a hotel. It is dorm style accommodations on the NUI campus. However you need not be a participant at the university to stay here. We booked a private double room ensuite. We were provided with clean towels, clean linens, bars of soap, and vials of shampoo. The bathroom was tiny by American standards but very clean. The small shower stall had a glass door and we had full force hot and cold water. Corrib Village is fairly close to Galway City and they provide free shuttles to the city. (If you are athletically minded it is a 40 minute walk to the city from the campus). The shuttle runs frequently from 12 pm onwards on weekdays and 10 am onwards on weekends. Just remember that the last shuttle is usually early —like 7-8 pm, but the cab ride is not too bad. It will cost about 10 €. The reception desk is friendly and check-in is easy. It being in a campus, there is a cafe on site that serves breakfast (just under 6€) and good coffee, and has a small store attached that sells a wide variety of snacks and necessities. A convenient laundromat is also on site. Booking for a minimum of 2 nights gives you an even better price for your lodging.
You can take day trips to the Cliffs of Mohr and the Aran Islands from Galway city. The Aran Islands ferry has an office right in the heart of the city. The Tourist info office is a great resource. Dublin is a three hour ride via bus.