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

https://dallasssplendidinsight.yousher.com/chatgpt-plus-vs-pro-is-pro-actually-smarter-or-just-more-quota

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