Tokyo Auto Salon

hi i need to go to osaka to tokyo return what is the cheapest way.
why jr pass so expensive…???
and from tokyo to tokyo auto salon on 12 janury the show at makuharri messe.

We have an article on this: Osaka to Tokyo: The Fastest and Cheapest Transport Options | Japan Cheapo
A JR pass is relatively cheap if you do lots of intercity travel, but not worth it for a single trip.
Not sure where you will be in Tokyo, but from Tokyo station to Makuhari, is only about 560yen on the train. Google Maps is your friend.