The big savings come when one leases a seat on the correlated exchange. It is not a hard calculation to see if it is worth it. If a trader is consistently trading volume for a few months we can help and offer a commission rate along with savings on exchange fees that will help the trader save quite a bit while still having a person to talk to/ communicate with etc. 24/6. https://www.cannontrading.com/services/match-beat-rates https://www.cannontrading.com/services/cme-membership-prices
What are the requirement and cost to lease such a seat? and would an options trader have to lease a seat on every single exchange he is using to guarantee best execution ? Bats, ISE, PSE, CBOE, EDGX, AMEX, PHLX....
This is more applicable for futures and options on futures. I am not familiar with how things work on the equity side.
I used to use Advantage and I think you can ask for a personalized quote still. Also, at least back a few years ago, the customer service was fantastic.