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

https://high-wiki.win/index.php/Why_Is_ChatGPT_Plus_$33.99_AUD_on_Android_in_Australia%3F

ChatGPT Plus is listed at $20 a month, but the actual price can vary between about $13 and $27 depending on where you subscribe. This difference mostly comes from extra charges like VAT or GST and fees added by app stores on iOS or Android