Thanks satprof!
I found this:
http://www.roundtheworldtickets.com/...d-first-class/
First class 6500GBP when starting the trip in low season like May.
This Discoverer First Class round the world fare allows you to circle the globe visiting Africa, the Far East, North America, Central America, South America and the South Pacific. It also allows unlimited extra stops within Australia (within the general mileage and sector rules of this RTW ), is valid for 12 months and is fully flexible – allowing date changes and unusually, re-routing. Prices & routes are valid low season (generally leaving the UK in May), & include tax & fuel surcharges – please call us on 020 7704 5700 for an accurate quote depending on when you are leaving the UK.
Not too bad. Have to check the explorer tickets as well and compare the routes.