ChatGPT Plus is listed at $20 per month, but you might pay between $13 and $27...

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

ChatGPT Plus is listed at $20 per month, but you might pay between $13 and $27 depending on where you subscribe. Differences come from taxes like VAT or GST and fees added by app stores such as Apple or Google