Summer is a bummer time to travel. I know lots of people travel Turkish Airlines nowadays from Asia to Europe coz they seem to be pretty cheap. Are you looking for single tickets? Just did a quick search from London to Melbourne return with Singapore Airlines and it's under £1k. Could you not travel the return leg, or leave it open? Alternatively, try flying long haul out from Europe because I hear London long haul fights are very expensive coz of all the taxes etc. Bristol has lots of flight to Europe so you can try hopping out from there.