Is it cheaper to upgrade at the gate?

Rarely. While 'operational upgrades' happen, they are random. Relying on them is a bad strategy; book your seat in the cabin you want.

When is the best time to book?

Awards are usually released 330–355 days in advance. If you don't book then, check again 14–21 days before departure when airlines release 'last-minute' unsold seats.

Are 'miles' the only way to get a deal?

No. Look for 'Business Class Flash Sales' via sites like Secret Flying or FlyerTalk. Sometimes airlines drop prices significantly to compete on specific routes.

How to Book Business Class Flights to Asia Without Breaking the Bank

Book your flights 6 to 9 months in advance using airline miles or credit card points transferred to partner programs. Avoid direct bookings with cash unless you find a significant fare sale, as these can easily exceed $5,000 round-trip.

Target the right airline alliances. Focus on the big three: Star Alliance (ANA, EVA Air), Oneworld (JAL, Cathay Pacific), and SkyTeam (Korean Air, China Airlines). Use the 'multi-city' or 'partner award' search tools on their websites.
Use award search tools. Stop searching airline sites one by one. Use aggregators like Point.me or AwardHacker to find which programs have open business class award seats for your specific route.
Master the 'transfer partner' strategy. Transfer your credit card points (Amex, Chase, Capital One) to an airline partner only after you have confirmed the award seat is available and bookable.
Positioning flights. If business class seats are unavailable from your home airport, search for departures from major hubs like LAX, SFO, JFK, or YVR. Book a separate, cheap economy flight to get yourself to that hub.

Is it cheaper to upgrade at the gate?: Rarely. While 'operational upgrades' happen, they are random. Relying on them is a bad strategy; book your seat in the cabin you want.
When is the best time to book?: Awards are usually released 330–355 days in advance. If you don't book then, check again 14–21 days before departure when airlines release 'last-minute' unsold seats.
Are 'miles' the only way to get a deal?: No. Look for 'Business Class Flash Sales' via sites like Secret Flying or FlyerTalk. Sometimes airlines drop prices significantly to compete on specific routes.