Re: Well you'd need to compare available income
€400 "warm" rent for 75m² is not all that expensive (relatively speaking). Depends on where you are. I'm at about €1000 per month for 88m² for a family of 4, but this is in southern Bavaria about an hour outside Munich.
As far comparing costs of living, I think Dublin is far more expensive. Healthcare and childcare here are brilliant compared to Ireland. Food is much cheaper, too.