In particular, it would be convenient for me to land in Dublin EIDW,
but I'm afraid of the costs of handling, of parking (seems to be 8€+
per hour !) and renting a vehicule (to be allowed to get to/from your
plane on the apron : 46€!)

Anyone here could share his/her first hand experience ?

You seem to be correct:
http://www.dublinairport.com/about-u...t_charges.html

For truly first hand information, why not just call them and ask?

Don't forget that Dublin is the home base of Ryanair, so they may be
actively discouraging private pilots to bother them.