What are the cheapest round trip flight options from Bangkok or U-Tapao Airport, and what are the visa requirements for visiting Phu Quoc, Vietnam?

The discussion focuses on finding the cheapest round-trip flights from Bangkok or U-Tapao Rayong–Pattaya International Airport, particularly to Phu Quoc, Vietnam. It is mentioned that flights to Cambodia (PNH) are typically cheaper than those to Phu Quoc (PQC). There are more flight options and potentially lower prices from Bangkok's two main airports (BKK and DMK). While Phu Quoc is generally visa-free for many visitors, travelers should check if they need a visa for the rest of Vietnam based on their nationality.