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

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

The listed price for ChatGPT Plus is $20 per month, but the actual cost you pay can vary from about $13 to $27. This difference comes from extra fees like VAT or GST in your region, plus app store charges when buying on iOS or Android