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

https://www.romeo-bookmarks.win/chatgpt-plus-is-listed-at-20-monthly-but-the-actual-price-you-pay-can-vary

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