ChatGPT Plus lists at $20 per month, but the actual price can range from about...

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

ChatGPT Plus lists at $20 per month, but the actual price can range from about $13 to $27 depending on where you subscribe. This difference mostly comes from taxes like VAT or GST and app store fees on iOS or Android