Please note that issuing tickets in Thailand and you want a 'discount' - most will give you a percentage back of their commission - with the sole exception of American Express Travel!
The commission level in Thailand is now 7% on a published fare ticket. The agents will net the ticket down - eg - say your ticket is Baht 250,000. The net fare will be less 7% of that Baht 232,500. Then they will add their commission on top of that first - then the taxes and then that will be total.
Please do not try and bargain with them - so will let you do it - but as a RTW ticket is so complicated, I feel sorry to have to ask them for a bigger discount! Thai agents, after booking it on their system, (I know it's tediosu) but they will need to fax the entire ticket to the issuing carrier - and trust me - they will refer to CX/BA/QF/AY depending on who is the first outbound carrier, and not the Oneworld airline of your choice to issue the ticket!
Oh yeah, before I forget - THAILAND travel agents will only accept CASH as payment!!!!
No creditcards permitted. Unless you issue the ticket directly with the airline - and thus in that case, no discount!