To be fair nobody's going to be able to give you a very detailed answer on that one without scrutinising the books and for most people life's too short.
Just to make a couple of points it has to be accepted that healthcare costs will rise incrementally. The population of Ireland has exploded and people are living longer, with multiple chronic illnesses. That costs money. By way of context, the NHS which I believe offers tremendous value for money have said they'll need an extra £30BN a year to stand still. They are achieving £22BN in efficiencies which still leaves an £8BN gap, just to stand still. Ireland are miles behind to begin with. I can see how it looks like throwing good money after bad without reform but apart from the one good thing Harney did of giving Tom Keane untrammelled power to sort out cancer services, we've been unable to do reform properly. Time to try something different.
In terms of specifics, I'd guess the HSE spends a fortune on agency staff because they aren't able to recruit and retain skilled ones. I have some sympathy for them here because this is entirely, 100%, totally the fault of James Reilly and the Labour Party.
