I have learnt something. Actually, I've never bought anything but the cheapest return in economy or business before and I'm not paying for this ticket but I have to produce a receipt for an economy flight and two boarding passes to be refunded so I was looking for an interesting workaround to maximise my return. I also want the tier points as I'm transitioning to Marco Polo from Enrich this year. So I've just bought the ticket and will get my tier points and the cost refunded. Haven't lost anything. Thanks for the insight.