As far as I know, the price of a project (currency/token) to enter an exchange is in the contract made by both parties, and depending on which cases and which exchanges, that amount cannot be revealed later as it will be in default of said contract and perhaps the exchange would eliminate the pairs with the currency of that project. On some websites I have read that Binance, for example, asks for a million dollars to add a new project to its exchange, and it may be true, I do not know, but that depends on many factors and the payment methods.