During my recent trip to Bangkok, I opted for data plan from AIS. I got the plan directly from AIS booth located in Suvarnabhumi airport.
The rate was as follows:
350 baht for 300MB of data plan including free call/sms of 87 baht.
The copy also provide the tired rate as follows:
– for 550baht you get 1GB of data which includes 73 baht of free call/sms.
– for 750baht you get 2GB of data which includes 59 baht of free call/sms.
– for 1050baht you get 4GB of data which includes 145 baht of free call/sms.
I had Wifi access at the place I am staying but the 300Mb ran out quickly within my 12 days stay there. My free call and sms also finish quickly. You may want to buy additional top up AIS prepaid card so that you can top up when the credit runs out.