ENR Quarterly cost reports are a very good source for estimating project costs if you just need a ballpark figure. The best source for this information is from several of your area suppliers. Nearly all of them would do backflips to get a heads-up on a possible new project.
Section 5 of the NAAMM Metal Stairs Manual has all the design information you require for steel stairs. It is availabl from The National Association of Architectural Metal Manufacturers.
