Just for a final bit of info..last year when checking campsites under haven.ie I rang an Irish company who told me that they book with haven.fr and the quote I was given was almost 1000 for 1 week less!! I guess the French just wouldn't pay 1700 euro for a mobile home!
The Irish Times featured an example of this yesterday in Conor Pope's weekly Pricewatch. He reported that a Keycamp " commendably upfront spokeswoman " said that the main reason was due to the fact that England had qualified for the World Cup and so the UK (June) prices have been heavily discounted! He went on to say a new Irish brochure will appear in March with discounts.