This is ignoring OpenAI's margins. We don't know how much GPT-3 and GPT-4 actually cost for them to run but it isn't what they are charging us. For Llama 2 the quoted cost is just compute, but for OpenAI you are also paying for using their software.
[Author] As an end user, you pay the published price of $1 per million tokens for alternatives (such as Anyscale Endpoints -- https://app.endpoints.anyscale.com/landing, but there are others -- Replikate, Fireworks etc). This isn't just the compute price -- there's some margin in there as well.