that will be the secret of the exchange because most exchange will disclose their actual listing fee.
i read on some article that said it cost 50 BTC or more to get listed on big exchange.
but in reality maybe it will cost more than that.

source : https://medium.com/assetrush/how-much-does-it-actually-cost-to-get-your-token-listed-51a63e2cbff9