Have been playing around with this one. Yesterday had it down to sub-£1000pp but that seems to have totally gone sine the Qatar sale started.
Brussels to Bangkok, Kuala Lumpur to Brussels. 560TP.
Works in a 787-8 & A380-800 fully flat beds in biz out, followed by A340 angled bed and 787-8 fully flat bed in biz return.
Connection out is tight at 1:05, return is early morning wait of 3:05. Nothing too extensive for the price.
Connecting flight BKK-KUL in Y is about £60pp / £125pp in J (which would total 600TPpp - Silver/Sapphire status all in one trip).
Others might find a way to get price down yet more.