We're planing to book two reward tickets between Shanghai and Tokyo in Jan. next year.

I know I need to call FB to make the reservation, since it's not possible to make an online reward booking between these two cities (using FB-miles). But before doing so, I want to know the facts, since I know calling FB-CS sometimes can be something of a gamble...

I know that you can spend miles with the following airlines using your FB-miles, and I also know that these airlines operates between Shanghai and Tokyo;

China Southern
JAL
Korean Air
Northwest Airlines


When you use the miles calculator over at KLM.com, you're given the info that one needs 35K for a return ticket in Y. But I can't find any information about the cost for taxes and fees. Would it be the same for all the airlines I'm mentioning above? I know that for example NWA charges you $109 for this return trip if using ones WorldPerks miles (which I personally don't have any)

So any help on this would be great. ^

Many thanks in advance.

Cheers,
Joe