ChatGPT Plus lists at $20 a month but may cost more depending on your country...

https://wiki-tonic.win/index.php/Is_ChatGPT_Plus_Ad-Free_Even_If_Free_and_Go_Show_Ads_in_the_US%3F

ChatGPT Plus lists at $20 a month but may cost more depending on your country and device. That’s because taxes like VAT or GST get added, and app stores charge extra fees when you subscribe through their apps