There are 3 ways to travel from Yangon to Bagan: airplane, bus and train. I guarantee flying is the best way. The price is higher than the other two, but you can get there in a shorter time.
The journey takes approximately 1 hour and 20 minutes and costs from US $ 80 to US $ 130 one way.
Yangon Airport is quite far from the city center of Yangon, and it usually takes about 45 minutes by taxi or bus, but traffic in the evening is very bad, and it takes about 1 hour and 30 minutes, so be sure to arrive at the airport early. (We missed the flight from Yangon to Bangkok this trip because of heavy traffic jam in Yangon…)