According to Vodafone while roaming on Ready To Go "texting" costs €0.49. Does this mean that it costs €0.49 to send a text and €0.49 to receive one? I can't seem to find any autooritative info on their website.
My recollection from my time as a vodafone customer is that it costs nothing to receive a text while abroad but it does cost more than usual to send one (as you said, 49c). I was a billpay customer, but don't think that would make a difference in this situation.
Edit: found this on the vodafone website (did a search for "text")
"It is free to receive a text message whether in the Republic of Ireland or abroad."
In relation to my original query it looks like receiving texts does not cost anything. At least as far as I can see from my own periodic RTG balances and the fact that even when my mother had no Meteor prepay credit left while abroad she was still able to receive texts.