Where can I view my current Apple subscription costs?

You can also go to your App Store Account Settings and look at your Subscriptions there. If you have Renewal Receipt Emails turned on, you might also have recent e-mail receipts that you could look at.

E.g.,

I am going to let you do the footwork here, particularly since I do not know which services you use. AppleTV+, for example, has a link Apple TV+ - Apple If you go to the bottom of the page there's a list of questions and if you click on "cost" it tells you how much. All of Apple's services tend to have that and sometimes you simply need to change the name of the service in the base URL

https://www.apple.com/apple-tv-plus/

iCloud+ plans and pricing - Apple Support

Apple Music - Apple

Scroll all the way to the bottom for pricing.