It's hard to gauge the thing for sure, but it also depend on how much business that location will bring. I remember hearing the shoplot in Kota Syahbandar in Melaka costing north of rm1 million per unit(3 storey) after they've done building the area and i first thought it will die off, but right now it's one of the busiest place in Melaka, replacing Melaka Raya.
The rental is high, but the potential of making a load of money is higher so people willing to take the risk.