I guess there's 3 potential reasons for this requirement, each with its own answer
- Destinations flown by BA
- Avios pricing
- Avios availability
1 is covered well by [MENTION=748878]email2markt[/MENTION]'s link above
2 you don't really have to worry about (for
direct flights from LON) unless you want SYD in F during peak times. Every other option is affordable (in Avios) with 350K and 2 x 2-4-1 for 4 pax.
3.
BA redemption finder will show you availability in your chosen cabin/route for next 12 months
One thing we get hung up on is where we could go with our miles/vouchers/etc. but is it somewhere you *want* to go?