Is it cheaper to upgrade at the gate?

Rarely. In modern aviation, airlines prefer to sell upgrades through their apps or websites 24-48 hours before departure. Gate upgrades are almost always full price.

Which airlines offer the best lie-flat seats?

EVA Air, Qatar Airways (Qsuite), and ANA are widely considered the gold standard for long-haul flights to Thailand.

Booking Business Class Flights to Thailand

To secure a business class seat to Thailand, set price alerts 6-8 months out and use airline miles or credit card points rather than paying cash. If paying cash, always use a metasearch engine to track fare fluctuations and aim for mid-week departures to save significantly.

Use specialized search tools. Avoid general travel sites. Use Google Flights or ITA Matrix to view the entire month’s calendar. Set a 'Track Prices' alert for your specific route so you are notified the moment a fare drops.
Target alliance hubs. Focus on the big three alliances: Star Alliance (Thai Airways, ANA, EVA Air), Oneworld (Cathay Pacific, Qatar, Japan Airlines), and SkyTeam (Korean Air, China Airlines). You will get better value by leveraging your existing frequent flyer points.
Leverage 'ex-origin' positioning. Business class fares from Bangkok to major cities are often cheaper than the reverse. If you plan on visiting Thailand multiple times, consider booking a round trip starting in Bangkok rather than starting from your home country.
Check business class consolidators. Sites like Kayak or specialized luxury flight aggregators can sometimes find 'bulk' rates that airlines don't publish directly, often saving 20% on the retail price.

Is it cheaper to upgrade at the gate?: Rarely. In modern aviation, airlines prefer to sell upgrades through their apps or websites 24-48 hours before departure. Gate upgrades are almost always full price.
Which airlines offer the best lie-flat seats?: EVA Air, Qatar Airways (Qsuite), and ANA are widely considered the gold standard for long-haul flights to Thailand.