indeed sometimes they are the founders of the exchange where the fee is required to register to the place of exchange, but I think it will be worth it when you register a coin in a trusted exchange and have a high trading volume because if registering at an exchange is not good it will not be as expected .
Bigger exchange site needs a lot of requirements or more fees. I should remind you that sometimes the big exchange site is also wanna offer a free listing event but it is not so easy as people said consider about the coin must be chosen and there were a lot of participants too.
A new project needs think for a twice to be registered on big exchange site