I wouldn't say that Qantas's award costs are cheap either - the rates are terrible compared to say AA awards which would be 87,500 for Australia to Europe - plus no fares disguised as taxes either
Upgrading from the full economy fare at 71,000 points is the only upgrade that I would consder - from discount it is just too overproced
If booked on SYD-LHR as a single coupon, I didn;t think that it allowed requesting an award for part of the journey