Classes like Gymboree, music, etc. and outings such as the zoo or children's museum can be expensive! We don't do those things often because I feel like she gets a lot of it at part-time daycare and when she's not there I would rather do low-key things together like the park or library story time mostly. But if I stayed home we would probably do a class or two.
If you are willing, comment with your household income and/or where you live as well!