Last time i checked CQG was $600 base fee, and then you start to add data and addons. So its more like $800-$1000 or more, depending on what you want.
It all depends on the API. Professional software development cost starts at $50/hour... So even a small trading operation with one (1) full time engineer... Is looking at a 6 figure annual tech budget. Not saying this is a good solution... But a quality data feed with quality API is easily worth $5,000 to $10,000/year. Free data like IB's is designed to fleece the lambs... Unreliable, possibly manipulated, no NBBO, etc. How can anyone trade without a quality NBBO quote in the fragmented markets of 2007?