Now cryptocurrency market raise and cryptocurrency is very popular, that is why there are so big prices on exchanges.

From the choice of exchange for listing depends the results of IEO. You must understand this.
As I understand it will be different stages of IEO on different exchanges. So investors will have a choice of exchanges.
Listing on different exchanges will attract more attention to the project and I think that listing is a good promotion to the project because traders pay attention to new projects with listing.