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

https://direct-wiki.win/index.php/Does_ChatGPT_Plus_Auto_Renew_After_a_Trial%3F_Your_Complete_Guide_to_Pricing_and_Subscriptions

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