ChatGPT Plus is listed at $20 per month, but what you pay can change depending...

https://penelopessmartdigests.talesignal.com/posts/why-does-google-play-add-cost-to-chatgpt-plus-if-google-takes-15

ChatGPT Plus is listed at $20 per month, but what you pay can change depending on your country and device. That’s because taxes like VAT or GST get added on top. If you subscribe via an app store, there’s also a markup included