Steve's prices are basically in the ballpark, here in the Kansas City area the price per foot ranges from $3.25/foot (subing the decks for new home construction), to $3.75/foot for existing home owners. Now one small question regarding the "cedar railing?", are we talking actual railing as in horizontal 2x4 or 2x6 boards? Or are we talking cedar spindles (2x2x42-48 inch)?
I agree with Steve with regards to using the all pressure treated for the "decking and rails and topcaps", but however, I prefer using cedar spindles. The reasoning being, the cedar will warp less than pressure treated, in any diminsions, but specifically 2x2 spindles! We send lots of CCA spindles back to the lumber company, because they are either warped, or split once you shoot a nail through them. Cedar tends to split a whole lot less, and will be straighter to start with and for the long haul. So if we are talking spindles, go with cedar, it's just under $2.00/42" each, compared with just under $1.00/42" each.
CCA will work just fine on the rest of the deck parts, just don't (in my opinion) skimp on the spindles. Also, ask that the builder either use 3" deck screws (prefable), or 12-16 penny ring shanked nails. If nailing, the ring shanked nails tend to pop out less, although they still manage to find their way out somewhat.