The Lower percentage of a brokerage fee, the Higher the minimum trading size becomes ! As a result, it seems like one should always pick an account type that matches his average trading size.
Wrong again ... I cann't stress enough that we need to analyse the real numbers to know the whole truth. Not just the concept.
Compare different brokerage fee offers in an old post
At the end, the lowest brokerage rate with the lowest minimum brokerage fee DOES equal to Maximum saving in this case !