ChatGPT Plus is listed at $20, but the actual price can vary between about $13...

https://www.third-bookmarks.win/chatgpt-plus-lists-at-20-a-month-but-the-actual-price-you-pay-can-vary-from-1

ChatGPT Plus is listed at $20, but the actual price can vary between about $13 and $27 depending on where you subscribe. This happens because of extra costs like VAT or GST taxes and app store fees from Apple or Google