Listing fee is really free, Binance just charge them for other fees that related on token trading liquidity since there’s market maker on exchange that will be assign for the token that they will list plus maintenance. These fees is not disclosed public but included on NDA of Binance to the project itself.
There are times that Binance voluntarily list a token that has a huge demand which migh be total free kf charges but this is very rare scenario.
I could tell you how much, it’s about 280 bitcoins. I didn't sign the NDA and yet I know it because some idiot in a project I used to work for told me, when he signed the NDA, and that means he is in trouble if Binance ever comes at him, but it doesn't matter to me lol. In the end we are talking about a HUGE amount.
This was of course during the bull run of last year, not this year and I think it's something that we are not willing to pay if it was our own project but when you do, you see the benefits of it. If betfury thinks they are profiting from it then they shouldn't be questioned, it's their money and let them do whatever they want with it and if they are happy about it, then they are doing it right.