The listed price for ChatGPT Plus is $20, but the actual cost you pay often...

https://wiki-legion.win/index.php/If_I_Take_a_ChatGPT_Plus_Trial,_Will_It_Charge_$20_After%3F

The listed price for ChatGPT Plus is $20, but the actual cost you pay often varies between $13 and $27. This happens because of things like local taxes (VAT or GST) and extra fees added by app stores like Apple’s or Google’s