What are the costs and procedures for Thai re-entry permits at immigration and at the airport?

A Multiple Re-entry Permit costs 3,800 baht, while a Single Re-entry Permit is 1,000 baht. Prices may vary slightly at airports due to a 200 baht convenience fee, but you can save this fee by completing the required forms in advance. You can purchase multiple Single Re-entry Permits if needed; however, you must return to Thailand before buying another. Planning between the two options depends on how many times you intend to exit and return, as there's a cost benefit analysis involved.