For cement you should order by the truckload, at least 600 bags to get the factory price, because dealers dont have to unload and load again, they can just get it from the factory and deliver straight to you. Six hundred bags is the load per 10 wheeler truck, and 1,000 bags is the load per trailer truck, so take your pick. For hollow blocks, you must choose whether you need load bearing at 700psi rating or non load bearing ordinary 300 psi rating, you can have them tested if they can meet the standard. Try calling Capitol steel for steel bars, have them quote, also get quote from Pag-asa Steel, Steel Asia, etc. for comparison.