ChatGPT Plus is listed at $20, but the actual price you pay can range from $13...

https://dibz.me/blog/is-there-a-chatgpt-plus-free-trial-i-can-click-to-start-1223

ChatGPT Plus is listed at $20, but the actual price you pay can range from $13 to $27. This difference is mainly due to taxes like VAT or GST and fees added by app stores, especially on iOS and Android