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

https://bravo-wiki.win/index.php/What_Is_the_Max_File_Size_for_ChatGPT_Plus_Uploads%3F

ChatGPT Plus lists at $20 per month, but the actual price you pay can range from about $13 to $27. This difference comes from added taxes like VAT or GST and extra fees charged by app stores such as Apple’s or Google’s