The listed price for ChatGPT Plus is $20, but the actual cost you pay often...

https://highstylife.com/i-keep-hitting-chatgpt-limits-should-i-start-a-new-thread/

The listed price for ChatGPT Plus is $20, but the actual cost you pay often varies between $13 and $27. This happens because of things like local taxes (VAT or GST) and extra fees added by app stores like Apple’s or Google’s