Originally Posted by nov11

I wouldn't know the pre-order price but those shops are legitimate telco operated shops (not third party shops as seavisionburma mentioned). What you pay at KLIA is probably what you'd pay on main street in KL. 5-10 MYR for a SIM card and whatever plan you want to choose. The "tourist package" is just a package offered by some telcos where they bundle your SIM with data package. You don't have to buy that if you don't want to.

I don't know where you'll be traveling in Malaysia but if you are only sticking to the metropolitan areas, then all 3 telcos work fine. If you travel to more remote areas e.g. islands off Sabah or jungles in Sabah/Sarawak/peninsula, you should check with the resort and see which telco company works best at that location. e.g. only Celcom works in Kinabatangan jungle area and some islands off Semporna in Sabah (e.g. Pom Pom Island).

Also worth noting that CelcomDigi is a merger of 2 companies, Celcom and Digi. I don't believe they have merged their network yet so it might be worth checking at the shop which exact network you are purchasing the SIM card for (Celcom or Digi).