The advertised ChatGPT Plus price is $20, but what you actually pay can range...

https://www.slideserve.com/aaron_ward92/why-does-chatgpt-plus-cost-more-on-android-than-on-the-web

The advertised ChatGPT Plus price is $20, but what you actually pay can range from about $13 to $27. This difference comes from factors like regional taxes (VAT or GST) and extra fees added by app stores