It isn't actually that much money, it only costs a few BTC to get listed. The main problem is how popular the project is which gives the exchange incentive to list it. They don't list any coins that won't have a larger trading volume as it won't make them any money, and they usually only list established projects that have been around a while and have proven themselves to be legitimate.
actually bro he's right. hitbtc are known to ask for more than 50p/c of ico collection and also a huge chunk of ico tokens to make things more tasty for them and most devs go for this because this is the baseline offer thrown out by the big dog exchanges. Its reeeaaaally stupid for devs to be accepting these kinds of offers because they are giving away control and putting the exchanges in the drivers seat which is dangerous and stupid. the exchange is not gonna develop your apps so y give them any control