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

https://www.bookmark-step.win/the-official-chatgpt-plus-price-is-20-per-month-but-what-you-actually-pay-can

ChatGPT Plus is listed at $20 per month, but the actual price you pay often varies between $13 and $27. This difference comes from extra taxes like VAT or GST and the fees added by app stores on iOS and Android