it's about there

a 4-stop elevator cost about rm 300k, exc GST, transport & installation

an 18-stop elevator will cost more, even though u only need 1 car, u need 18 stainless automatic door, longer wire ropes

then you need the wiring for the lift motor room, automation, emergency call system, testing & comm, JKKP certification, and all that

which leaves you with about rm 100k profit per eleveaotr

1.8M profit over 15.2m = 12% margin is not much. if it is me, i'd aim for at least 25 - 30%