I am assuming this is an economy-class ticket, not a business-class one, right?

You can save around £300 on the base fare for an LONE4 by starting in the Euro zone as opposed to the UK. For example, this itinerary - AMS-DOH-CMB,NRT-HAN,SIN-MEL,BNE-ZQN,AKL-SCL-GIG-EZE-LIM-UIO-MAD-AMS passes muster and avoids BA fuel surcharges as well as UK departure taxes. You can fly to Amsterdam from London for £50-60, so you're still ahead on the base price.