I would appreciate if someone share his/her knowledge on this matter "Why different brokers/prop.firms charge different exchange fee. Thank you for your information in advance.
probably because the prop is not providing full pass thru of ECN fees and is skimming from the top. You can always go to the ECN to see what their fee schedule is and compare it to what your prop is passing thru to see if/how much you are cheated by your firm.
There are actual firms who do that ? wow. I should probably add that a trader who doesn't know ECN fees ... eesh.
yeah they do. Example - compare the fees from this firm against the actual ecns or even other firms (prop and retail) to see how they don't pass thru fees w/o skimming: http://www.broadstreettrading.com/ecn.htm
Also, as a trader, you need to keep up on the fees and constantly make sure they are correct. I have had a few times that the ECN changed a charge and my firm didn't pick it up right away.