Does anybody know if it's possible to buy single packs of cigarettes airside BKK?
Family Mart landside or nothing then!
I'm confused by your use of "airside" and "landside"?
Will you be staying in the international transit area? Or you have some DOM-INTL connection? Or originating in Bangkok?
No clue if the convenience stores in the international transit area sell single packs?
I assume that the Family Mart/7-11 landside do sell single packs, but be aware that tobacco products cannot be displayed here (excluding DF obviously) - they are hidden behind a vertical venetian blind sort of contraption, so you'll have to ask specifically to view the selection.
Smoking Areas in Bangkok / Suvarnabhumi International Airport
No idea what will happen with the new smoking laws, assume they'll exempt the airport(s) and/or build enclosed rooms?