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

https://www.bookmark-xray.win/the-listed-price-for-chatgpt-plus-is-20-per-month-but-the-actual-cost-can

ChatGPT Plus is listed at $20 a month, but the actual price you pay can vary between $13 and $27 depending on where you sign up. Differences in taxes like VAT or GST and app store fees can change the final cost