From Tan Son Nhat (SGN) to District 1, Grab is 200,000–300,000 VND. Airport taxi tout 'flat rates' are often 500k+.
Walk to the rideshare pickup zone (signposted). The taxi-tout area inside the terminal is full of pushy drivers.
Mai Linh and Vinasun official taxi counters inside the arrivals hall are also fine and use the meter.