How far does 100 US dollars go in Thailand? In Thailand, $100 USD can get you 60-140 one-way trips on the Bangkok Railway System (BTS/MRT), 2-3 one way flights between Bangkok and Phuket. How much cash is allowed in Thailand? For Thai currency (Baht), any person can bring a total amount not exceeding 500,000 THB to countries bordering Thailand and not exceeding 50,000 THB to...