Osaka To Tokyo (Return)

To travel from Osaka and Tokyo (same day return trip), which option is better and cheaper? Domestic flight or train? Thanks

I think about 75% of business travelers opt for the shinkansen on this particular route. About 25% for the plane. Time and cost wise, there is not much difference.

Your options:
http://www.japan-guide.com/e/e4006.html

From Osaka to Tokyo, according to Hyperdia, it will be 13,240 yen ONE WAY, for non-reserved seat.

Keep in mind this is only from Osaka station to Tokyo station. If you need to travel to Narita airport, for instance, it will be more.

To compare to airlines, I would suggest checking prices on Orbitz.com, travelocity.com or comparable site. Keep in mind that fuel surcharges are very high on planes at the moment so make sure you're looking at the whole price when checking those website (tax + surcharge should be disclosed).

If you fly, of course, you should use Haneda Airport, unless you are located around Narita.

Depending on where in Osaka you are heading, Itami, Kansai or even Kobe Airport might be most convenient. Generally speaking, Itami is most centrally located.