You should also check travelling from other cities in Europe as prices differ. I flew a RTW from Gibraltar and got over £1000 off the UK price. Just contact Bland Travel. This year I'm departing from Stockholm and saving a budle. If you want the travel agents details let me know as I don't have the to hand.
I think prices have gone up, but if you look on the one world forum they have a link to the latest prices from each country in world.
Both times, the trip has been organised without a hitch.