I am not aware that Bittrex is charging that much for trading...all I know is that the charge per transaction is very minimal. I have been using Bittrex since I got enamored with trading many months ago and I still do some trading from time to time with Bittrex since it is very newbie friendly.
Are you talking perhaps with withdrawing your Bitcoin from these exchanges to your own personal Bitcoin wallet? I am aware that there is already a significant reduction of fees since the Segwit was activated many days ago and come November we would have another upgrade that can hopefully deal with making the transactions faster as it should be and that can result into lower fees since there would be less clogging.