This is from a 10 year old MSC article (quick search on AISC.org), I think I may call a local steel fab you have worked with to ballpark you a couple of numbers for steel stud installation and for steel tonnage costs:
Favor the use of partially composite
action in beam design. Although shear
stud installation costs vary widely by
region, on average, one installed shear
stud equates to 10 lb of steel. Fully composite
designs are not usually the most
economical because the average weight
savings per stud is less than 10 lb.
Modern Steel Construction / April 2000
Figure 2. Web penetration reinforcement of an I-shaped beam.
Sometimes, the average weight savings
per stud for 50 to 75 percent composite
beams can exceed the point of equivalency.
In some cases, non-composite construction
can be most economical. A
caveat: make sure that the beam in a
composite design is adequate to carry the
weight of the wet concrete.
• When composite construction is
specified, the size, spacing, quantity
and pattern of placement of shear stud
connectors should be specified. It
should also be compatible with the type
and orientation of the steel deck used.
When evaluating the relative economy of
composite construction, keep in mind
that most shear stud connector installers
charge a minimum daily fee. So, unless
there are enough shear stud connectors
on a job to warrant at least a day’s work,
it may be more economical to specify a
heavier non-composite beam.