Ireland is great. I spent a week there with my father - best vacation I've had in quite a while. We spent two days in Dublin, and then rented a car, drove west, and then came back to Dublin by following the coast to the South, stopping each night in small villages. It still has sights that seem unreal, or prolonged moments of silence that can be quite eerie. Nevertheless, it was simply amazing. As for your money needs - unless you plan on going through UK, Ireland has the Euro now. Even with that, the country remains quite expensive. I can't comment on the time you chose to travel - We were sightseeing, so we expressely avoided periods that are heavy with tourists, such as June to early September.
Don't miss the fruit crumble if you go through there

Oh. Another thing. Best night we had was when we decided to try out one of those upper scale Bed & Breakfasts. It turned out it was in an ancient and gorgeous mansion in the middle of nowhere. And the weather that day really agreed with what you might think of Ireland - it was windy and dark. To top it all, the same night we went to a genuine, honest-to-god Irish pub. You could see the people there had been there their whole life, and the feeling was surreal.
I hope you have an excellent trip - the country is worth it!
PS : On a side note - for any men thinking they can go there and pick up chicks... Well, you might. I, however, in a WHOLE week, saw not ONE (1) good-looking woman.