I got a re-entry at Jomtien in July and I needed:
- application form
- copy of passport ID page, visa stamp, extension stamp
- copy of TM30
- photo
- 3800 baht for multiple re-entry (single re-entry is 1000)
I went to info desk at 2:15 for doc check and get ticket #, saw IO by 2:30, passport ready about 3:20