If you're subcontracting and getting paid corp-to-corp they shouldn't be skimming much off the top. I'm just pretty sure that the market rate for a senior Java dev or team lead with 7+ years of experience is a lot higher than the pre-tax corp-to-corp numbers mentioned, even in Chicago. I have front end dev friends who make much more than that, just doing CSS/HTML work.
I guess they are skimming. I have negotiated, and they don't accept my desired rate. My current contract used the recession as an excuse to lower my rate. And, I was out of work in Jan and Feb due to hardly any contracts in Chicago and no one accepting my rate. May I send you my resume for you to quickly glance at it?
A) You aren't very good (or at least aren't as skilled/productive as other folks with 7 years of experience)
or
B) You really need to learn how to negotiate better
For a senior Java dev with 7 years of experience in Chicago, you should get much more than that for corp-to-corp.