I use to go to Mitsuwa and Marukai in Costa Mesa, CA all the time. In fact, I had a lot of experience with Japanese food before learning the language. I thought somethings were expensive, but not that bad. After living in Japan I've realized how expensive things are.
Pet bottles of tea or coffee are about $2.25 Mochi is like $10. Small bottles of Kewpie mayo were $2.
But somethings were insane.
Japanese brand tissues. 5 boxes for $6.
Yebisu 6-pack $19
And... not so insane but, Calpis is called Calpico in the US.