Is it still possible to get a re-entry stamp at Suvarnabhumi Airport, and what are the costs involved?

Yes, you can obtain a re-entry permit at Suvarnabhumi Airport, located past the immigration desk in Departure 2. The process involves notifying the immigration officer that you need a re-entry permit. The cost is 1,000 THB if you have the necessary forms, and 1,200 THB if you require assistance in filling them out. The service is available 24/7.