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

https://suprmind.ai/hub/chatgpt/pricing/chatgpt-plus-price/

ChatGPT Plus lists at $20 per month, but the actual price you pay can vary from about $13 to $27. This happens because of taxes like VAT or GST and additional fees applied by app stores on iOS or Android