You can get a local SIM card inside the airport right after you get your luggage x-ray as you leave, but before you exit outside. You may pay a little more, but it's still fairly cheap. There are cell phone shops all over the city as well. I usually just have a relative or friend get me a pre-pay SIM and I just top it off as I go. I am sure the concierge at the hotel can help you out too. Just opt for the data heavy package since I doubt that you will use voice much. For two days, $5 or $10 USD should be sufficient.