Re: I just purchased a different iCloud storage plan for $2.99. My previous storage was .99.
A new charge came through for $2.03
The price in your country's currency may differ from the USD$ prices listed.
(Possibly at only 99c month, the exchange rate then may have resulted in a similarity of the charge)
See: iCloud+ plans and pricing - Apple Support for the prices in various countries.
or
See: Countries and regions where iCloud storage plans are billed in USD - Apple Support
_____________________________________
Re: Was there tax charged on this amount?
We are all Apple users, like yourself in the community, so we have no access to your accounts or details.
I do not know whether tax is involved or not. (You may have an invoice in your email ?)
______________________________________
If needed: iCloud Support have a web-page online (info. support / contact options etc.) the link is below:
iCloud - Official Apple Support