In practical terms, assuming my IO follows suit, I guess I can expect to pay at least 1,000 baht tip to avoid the need to go away and come back. Last extension/reentry permit was the first time my IO required a bank statement. This I had forgotten but 500 baht saved the day, my petrol and temper. Plus, my IO filled out my forms and made the photocopies at his desk as he went along. I was very happy with the service provided.