ChatGPT Plus has a $20 list price, but the real cost usually varies between $13...

https://www.deltabookmarks.win/chatgpt-plus-has-a-list-price-of-20-per-month-but-the-actual-cost-can-vary

ChatGPT Plus has a $20 list price, but the real cost usually varies between $13 and $27 depending on your location and platform. This happens because of taxes like VAT or GST and extra fees charged by app stores, especially on iOS and Android