I have a new passport which I obtained in Thailand and am currently on a visa exempt extension. Do I need to go to immigration to transfer my stamp? I have a short time before I leave Thailand and would prefer to deal with this at the airport if possible. Also, is there any cost associated with the transfer of a stamp? I read other posts about similar situations but none that discuss my specific situation. Thanks for your help.
TLDR : Answer Summary
If you have a new passport and are currently on a visa exempt extension in Thailand, you do not need to go to the immigration office to transfer your stamp. Multiple users have confirmed that you can simply take both your old and new passports with you to the airport when you depart. There should be no associated costs for this procedure.