Yeah I recently paid nearly $100 for two people to visit the Chicago Field Museum and it was pretty disappointing. I'd guess well over half the exhibits are basically unchanged since I was a kid over 40 years ago, and it showed.
If you haven't been, highly recommend a visit. Especially if you're brining kids - hard not to have a good time when you can walk into a water vapor tornado.
Good lord. Yup, $43/head if you want to see all the "ticketed exhibitions". (Is there sales tax too? Sometimes museums don't.)
Beyond just the prices, I really don't like the new spreading trend of charging more for "current exhibitions" separate from the rest of the museum. The Field Museum is "only" $30 for basic admission that excludes those.