But than with an even larger volume and rebates, IB should become cheaper. Otherwise, from memory, at standard pricing, it's 0.1% commission or 29euros max per transaction in several european countries, and some countries without maximun commission . More info : http://www.interactivebrokers.com/en/p.php?f=commission
IB is the cheapest game in town for active traders. With that, they can treat you how they want with their "lovely" customer service they're so known for. Conversely, if you're moving large volume through IB, you'll get treated better. The power of money...
RTS is just a software vendor like TT isn't it? It connects you to the exchanges and you pay for the data from the exchange. You still then need to choose a clearing firm who support RTS to be able to do any trading, think Marex does from memory if you're just after futures and options but then their in house platform would be cheaper.
How big of an account are you talking? If it's worthwhile, talk to Newedge, Penson, MFG - any of the big houses - and you'll get margin and global access.
Thanks Ogarbitrage, I will look into those - actually had a first look at 2 of the websites and it seems they look for different kind of customers - first one quite big accounts but the other also small retail customers.
If your volumes are there, there are some choices for you. There are professional introducing brokers that take institutional accounts. With these accounts you can trade what ever you want. If there is enough volume, the broker can set it up for you.