Apologies for the new thread but I couldnt find clear information elsewhere - or alternatively I may simply be too dumb to see what's in front of me :-)

In the past (a couple of years ago now), when I bought RTW fares in business class, the Oneworld website made it quite easy to see the cost of a 3-continent fare in business; I believe it was also possible to to see where it was a bit cheaper to start from (in my case Taiwan rather than Hong Kong because of the easy connection to the start point). It used to cost around USD 7-8,000 to go RTW.
Am I right in thinking that it has become almost impossible to work this out now? When I look at the Oneworld itinerary validator (which is in principle a good thing), I only get to know the fare after I've put in all my flights. For example, putting in an itinerary Taipei-HK-London-NY-Tokyo-Taipei cost me the equivalent of USD 20,000 whereas creating an itinerary that had several more flights inside Europe and several more inside the US (more segments overall) came to around USD 10,000. I know fares have gone up in the last couple of years so I guess today's $10k is the $7-8k I used to pay in the past. But $20k seems way too much for a D class RTW and the process of creating the itinerary before you know what it will cost (and therefore realise that the exercise was pointless) is somewhat frustrating.

Am I doing something wrong or missing something that makes the whole process easier?

Many thanks.