First of all $4 round turn is a very good commission for a %k account. The .99 commission rates you see don't include exchange fees and are probably .99 per side. As far as an llc, you can pay .88 exchange fees if you are a 106R cme member. You need to compare apples to apples.
When choosing a broker make sure that he Supports Strategy Runner To make sure the your broker is a certified Strategy Runner Partner Look for him on our Partners Page: http://www.strategyrunner.com/Content/partners If your broker is not listed on our partners page and you would like to use StrategyRunner with your current broker please send an email to: info@strategyrunner.com