ChatGPT Plus lists at $20 a month, but the actual price you pay can vary from...

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

ChatGPT Plus lists at $20 a month, but the actual price you pay can vary from about $13 to $27. This difference happens because of extra taxes like VAT or GST in your country and fees added by app stores like Apple or Google