I recently purchased the 2013 RS Means Building Construction Cost Data book from Amazon at a nice discount, and it's well worth the price... a wealth of information. However, they don't break out steel fabrication labor cost from the bare cost of materials. Bare material costs include mill base price, mill extras, transportation to the shop, shop drawings and detailing, shop fabrication, sandblasting and primer paint, bolts and delivery to the jobsite. Bare material cost also depends on the size and type of project, type of structural components, bolted vs. welded connections. etc.
I'm not sure how you'd get this information without talking to a specific fabricator, but his cost might not be indicative of others... no easy answer here.