"If it succeeds in slurping O2 Ireland, it'll reduce the number of operators in the country from four to three, with just Meteor and Vodafone as rivals, potentially reducing the amount of competition and therefore hiking prices for users"
I don't think so if the example set in the UK is anything to go by - while the 'old boys network' which runs the main operators here have been price fixing for years, 3 has been very much the outsider aggressively and consistently undercutting prices...