How can ERC20 sustain themselves if fees are paid in ETH?

Hello guys. I have this doubt that maybe is a bit naive. I'm sorry for my ignorance, I'm just trying to learn… I was thinking about how could ERC20 tokens could sustain themselves if the ETH gas fees are so high in order to make a transaction.

I'll explain myself better. Let's say that I created an ERC20 token, let's call it GreatToken. Now, I want to make it available on an exchange. Let's say that someone wants to buy 5$ of GreatToken and that it is valued 0.000008$. So, now I have to send 625000 GreatToken to a specific address on the ETH main-net. Now, I have to make the transaction. Let's also say that the set gas price is between 1 and 77000 gwei. If my calcs are correct, I can actually pay a minimum of 0 ETH and a maximum of 0,26719 ETH (at the current value of ETH).

So, since I have to pay transactions fees using the native tokens of the network, in this case ETH, how is it sustainable for the new token itself? Is it possible to make the buyer pay the fee? Furthermore, how could I calculate how much money I'd need to guarantee all transactions?