Mmmhhh...
Qantas UK are not likely to find experienced crew for 18K. London Heathrow is an expensive base! As a junior with a charter airline, I used to take home 15-16k per year, living around Gatwick, which is a cheaper area than LHR. I wouldn't spit on an 18K contract if I had nothing else to go for but I wouldn't leave my job for that! It sounds more like a package for 1st timers... Sorry Qantas!
FJ (not such a cheap labourer after all!)