ChatGPT Plus lists for $20 a month, but the final price you pay can range from...

https://sticky-wiki.win/index.php/Why_Did_My_VAT_Exemption_Get_Rejected_for_OpenAI%3F

ChatGPT Plus lists for $20 a month, but the final price you pay can range from about $13 to $27 depending on where you buy it. This happens because extra taxes like VAT or GST are added, and app stores often charge a markup