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

https://www.yankee-bookmarkings.win/chatgpt-plus-is-listed-at-20-but-the-actual-price-you-pay-can-range-from-13

ChatGPT Plus is listed at $20 per month, but the actual price you pay can vary between about $13 and $27. This difference comes from extra fees like VAT or GST and app store markups on iOS and Android