Have you considered Lite-Deck? I got a quote for $4/sq ft for the materials (foam and steel stud stiffeners). This doesn't include the concrete or rebar. The span tables show it will easily span 10' with #4 or #5 rebar.
I ended up deciding to use wood floor trusses in my home rather than Lite-Deck, so I have no first hand experience with it.http://www.litedeck.com/about.html