The idea of ever creating my own cryptocurrency exchange platform has crossed my mind once but I don't have any idea how that can be possible and so I abandoned the thought because I think that it will be so expensive to do.
You need to be a developer and expert in the blockchain in order to create your own crypto currency. I am not one of them. I have no interest in crating my own crypto currency, even if I could, because I do not think I can survive the competition.
I don't even have in my plans and preparations to create any cryptocurrency exchanges. But generally the cost of creating a cryptocurrency exchanges is between 10 to 50 thousand dollars depending on how you want it to be.