flight prices will range from 470 euros to 570 euros per person depending on airline and exact date - (you didnt say return date; flights quite heavey on last days of school holidays).
Direct flights with Aer Lingus nearer to 700 p.p. euros depending on date- and assuming Aer Lingus are still operating long haul flights or not on strike...
Accommodation for two weeks - from 700 total squashed in one room (how old are kids?)
to 1.000 - 1.300 total depending on quality,facilities, location.
Car-hire -always dodgy with loads of extras (many of them that they try to make you pay when you pick up the car), but 500 will is a safe bet for standard saloon for two weks over Easter.
So, depending on your budget you are looking at anything from 4.000 to over 5.000 for five persons for two weeks for flights, accommodation ,car hie inc. all taxes..
Easter weather is fine but crowds and queues can be awful.
June weather is not that bad -especially early June. It does get hotter,stickier -and wetter a month or so later. And far less crowds- and a bit cheaper ... (especially if you avail of Expedia's "special deals" as discussed in this blog !!)
Tell me what quotes you get .