I carry a dongle and buy the limitless data plan for a month at 240,000 dong. When I leave just pass to fb for her to use. Use the the lady at the vn mobiphone she speaks English well.
I once used the guy at the corner next to the door and he charged high and was very abrupt.
For first timers who don't speak vn like me buy the taxi ticket at the counter too. It's cheaper as the toll is included.
Hope that helps.
