I pay $50/month for unlimited calling, text, and data (5GB LTE speeds, then 2G) on T-Mobile. I pay outright for the phone (had a GalaxyNexus, moved to iPhone 5s). Its really not a bad deal.
With 20€ per month on Ireland (pre-payed) one can get 250Mb AND Free calls in the network + free texts AND the 20€ for calls to other networks http://www.meteor.ie/pay-as-you-go/anytime-all-in/?linkid=pa... (if you go contract, the 20€ get you 1Gb Internet + 200Mins + Unlimited texts)
Disclaimer: T-Mobile customer for 13 years.