And now they are enticing users to register on their exchange having the promise of getting cash reward of $500. But wait, it is not really in the form of $$$s but in the form of their token. I wonder how much would it be later on? Would it fetch even 25% of its promised price?

They don't have to give extra extra rewards if they know they are doing their business right.
I think that getting a certain amount of coins just for registering on an exchange is an excellent advertising move. Let this amount be less than $ 500, even 100 times. It will still interest many.
Or receive double bonuses from the deposit, its also possible, people really like this