I'm also really shocked at the affordability of attractions in Japan. I thought we'd be getting absolutely killed by entrance fees but all the museums, aquariums, water parks, etc are cheap compared to North America.
Regular adult entry into Disney Japan ranges from $9000-10,000 Yen or about $80-$85 CAD. I can get my family of 5 in for around $250-$300/day CAD.
Regular adult entry into Disneyland or DisneyWorld in the States is more than double that. I was told by a recent family friend to budget around $1000/day CAD for a family of 4 just to get in.