The guy who pays the bribe = 50,000 ex pats.
The immigration officer = every IO office in Thailand.
The agent = 1000s of working Thais.
The "problem" all stems from the absurd 800/400k rule. Who benefits? The banks. My bags are packed if they ever enforced it. I'd simply take my money elsewhere, and become an occasional visitor, if I still felt it was worth it. I don't remember who brought it in, or when, or why. On average, I spend that 800k every year. In Thailand, almost all of it going to Thais. In the bank? You've got to be joking! I lose 10s of thousands in depreciation. My 12.5k would feed a family of 4 for a month, at least - if I chose to go down that route, of course.