I didn't get into UCD in the end but if you get in, fair play to you!! They're so bloody fussy with candidates. The only person I know who got in did so with 4As at A level.
However, she didn't end up taking the place and went to Liverpool in the end where I met her. I think she was warned by a vet she knew who went to UCD that Dublin was really expensive to live in and nobody really went out all that much because it's so expensive.
Sorry I can't give you any better advice but it will be expensive (as you probably already know) and there's cheaper places to live! Plus, I don't like the Dublin accent hehe!!
Good luck!