here is serious kopitiam. so should be fine. plus sharing is caring. I notice a lot of pipu have misconception on construction industry. heard i'll get promoted to elite if I continue to do this.

steel structure at abt RM7/kg, while in reinforced concrete, the rebar is abt RM3.5/kg plus u actually use lesser weight of rebar as it is a combination of rebar and concrete.

general estimation (not 100% accurate but is abt there, market price in big volume)

brickwall RM45/m2
glass is RM450/m2 (RM250 aluminium and frame + RM200 tempered glazing) low-e double glazing type will cost double on the glazing itself.

straight away u can build sub-structure. the set of foundation structure is the thing matter than u wait the land set.

cost budgeting, u need to have budget first. define the area u wanna build i.e. 2000sqft then allow a budget by 2000sqft x RM150. (the cost is vary depend on the quality u want. from this budget only start to work on the rest. this can be done through feasibility study, i did elaborate a little bit in previous post.

contractor, get those design and build 1 stop do everything including they hire architect and runner for approval relevant to local authority.