Well, Knott's Berry Farm would push your budget, but it is close to $100 (about $125 for tickets)
www.visitbuenapark.com
Maybe the Aquarium of the Pacific in Long Beach, admission is about $80, though I would try and up the budget to get the combo Museum/Whale Watch tour, and then explore the area.
www.visitlongbeach.com
Museums, the Bowers is World Class.
www.bowers.org
The Mission San Juan Capristrano is unique, then you could drive east on Highway 74 through the Cleveland NationalForest.
http://www.missionsjc.com/
A day at the beach, I like the Balboa Pier area of Newport Beach, close to
Disneyland, and some fun things to do, including taking the Balboa Ferry. Also, you can get a great deal on Whale Watching. $13 per person. Also ExploreOcean is available, part of the Discovery Cube group of science centers.
http://tinyurl.com/zvgveqv
The Santa Ana Zoo is close by.
http://santaanazoo.org/
Adventure City is also close by...
http://www.adventurecity.com/
So there are some of the many choices, with a lot of variety.