ChatGPT Plus is listed at $20 per month, but the actual price can vary between...

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

ChatGPT Plus is listed at $20 per month, but the actual price can vary between about $13 and $27 depending on your location and platform. The main reason is extra taxes like VAT or GST, and app stores like Apple and Google add their own fees