In managed futures the standard benchmark is "Round turn trades per year, per million dollars of account equity". For my trading style it's about 1800 RT/Y/$M. Figuring a global average of $10 commissions per round turn (which includes the RAPISTS who set commissions on the Japanese Govt Bond futures), that's $18K per year, per million dollars of account equity. In other words, one point eight percent: 18K/1000K = 1.8%.
Just a rough estimate off the top of my head, ~$6000-$8000. (100k shares a day+sec fees+conversion fees+ecn fees+SAI fees (firm short product))
I dont see why commissions matter. If you pay $50 RT, but make $1,000 RT due to the research you get, isnt it worth it? If you pay $50 RT but can sleep at night knowing that your FCM wont go belly up in the middle of the night, isnt it worth it? If you endlessly beat up your broker on costs, in the end, they'll beat you up. Pay a fair price always.