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

https://www.kilobookmarks.win/chatgpt-plus-has-a-20-list-price-but-the-actual-cost-you-pay-can-range-from

ChatGPT Plus is listed at $20 per month, but the actual price you pay can vary between $13 and $27. This depends on factors like local taxes (VAT or GST) and platform fees if you subscribe through the iOS or Android app stores