Why would you get a one-way ticket for a 2 week holiday? They're usually about 70% the price of a return ticket.
I checked some random dates for the month and it seems to be about $1,500 for Qantas and British Airways (return Perth to London).
That's impressive. We're planning a 3 month trip at the end of this year and I thought $5000 for accommodation for 2 people was good. I presume it was mainly dorms?
I'm finding spending money to be the killer in terms of costs.