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

https://alpha-wiki.win/index.php/ChatGPT_Plus_vs_Pro:_Is_Pro_Actually_Smarter_or_Just_More_Quota%3F

ChatGPT Plus is listed at $20 per month, but the actual price you pay can range from about $13 to $27. This happens because of extra taxes like VAT or GST depending on where you live, and app stores like Apple’s or Google’s add their own fees