0.03 to 0.05
that is alot
depends on yoru trading style i guess
and you can make alot of $$$ just taking penny gains
i just started trading about 6 month ago ... for the last 2 month i average about $700 a day ... i trade RBAK or SIRI.... 9000 shares... 1 penny makes me $90 plus credit which is $36
so 1 round trip i can make $125.. and i average 150 trades a day ... so 0.03 per trade you can defintely make money if you are good enough