Like to know best travel time Shanghai to Bejing ie by bullet train or flight. Any price difference.

Personally, the best or high travel time is around late Sep. to Oct. Bullet train fare varies a little all around the year. But for air ticket, there will be large differences. In high season, the air ticket will be much more costly than usual.

As you are traveling in Sep. the bullet train ticket is the same as usual. Flight fare costs higher than July or Aug.

For fare details, you can search out at the flights and trains pages in this website.