ChatGPT Plus has a list price of $20, but the actual amount you pay often...

https://wool-wiki.win/index.php/Why_Can_the_Same_ChatGPT_Account_Have_Three_Different_Prices%3F

ChatGPT Plus has a list price of $20, but the actual amount you pay often ranges from about $13 to $27. This difference depends mostly on extra costs like VAT or GST taxes and additional fees from app stores like Apple or Google