coarse osprey
Just as an FYI, your website still displays $20 when in actuality its $24 now. Might want to fix that to avoid being labeled false advertising 
👁️ , my card declined once because of this. I feel sorry for those that didn't notice it in their bank accounts in time being locked out of GPT 4 (waitlist) lmaoooooooooo 
viral geyser
From the flag I'm assuming you're in the UK (as am I) and this seems to be a UK-US cultural difference as much as anything
The extra $4 is 20% VAT; I believe the custom in America is to always give prices pre tax (in shops etc) whereas over here we would give prices post tax
Tbf my rule of thumb is if I see something for $X online I assume the VAT and exchange rates cancel (they roughly do) and just read it as £X - it might be better if OpenAI made the pricing here clearer but it's not really false advertising or illegal to my knowledge