Originally my cellular plan cost 40 dollars per month with 6GB of data, which was a good deal if all that data were used. I do not travel outside the campus and the dorm very often. 6GB data seemed too much.
Plus I was being constantly bombarded by the Google Fi advertisement on YouTube. Since I do not need all that much data, Google Fi seems to be a good choice for only 20 dollars a month plus 10 dollars per GB of data if I use the data.
Google Fi has global coverage and charges the same as in U.S, except making phone calls and texting messages. But still, the price is reasonable.