On EE I’m currently getting unlimited texts/calls and 30GB of data (with roaming in EU and US) for £17.99/month (~$25/month). Makes US prices look crazy.
They have a clause in the fine print, that says that you have to be in your home country at least once a month, in order to use this service. I thought it was great for me staying abroad for 6 months, but I could only use it for a little more than the first.