Dublin has a wide range of good quality restaurants, most of which are, however, horribly overpriced by European standards. Main course prices range from ?10 at the lower end up to around ?40 at the higher end. Wine in restaurants is generally marked up from its already expensive retail price by a factor of at least two and three times retail price would not be uncommon.
There are many excellent value Indian restaurants around the South William Street area, parallel to Grafton Street. These often have reasonable priced lunch and 'early bird' deals, offering three course meals for around ?10. Quality is high but not on a par with UK. Particularly to be recommended are the Khyber Tandoori on South William Street and Shalimar on South Great Georges Street. Also excellent is Surma on Camden St and "Govindas" on Augnier Street for very cheap Hare-Krishna vegetarian food. all are in Dublin 2.
A similar multi-cultural hotspot is Parnell Street in Dublin 1 (O'Connell Street-Gardiner Street), which has a dense concentration of Chinese and Asian restaurants extensively frequented by the ex-pat communities.
Don't forget to try Leo Burdock Fish and Chips (2 Werburgh St). There is no eating in, so I have taken my fish to Christ Church Cathedral and ate it on a bench. About 10 Euro for way too much food (share it with someone).