I think it would be more accurate if u could include the actual forex rates as comparison to be able to tell whether the Exchangers is giving a good rate..
Now on forex, S$1 : 23.3836 TWD
Now Mustafa offer, S$1 : 22.72727TWD
Difference is 0.65633TWD.. This is what mustafa made for every S$1
If the difference is lesser, that means the particular exchanger is earning less thus better rates.. and ofcos rates depends on forex..
Hope this will be easier for those who is trying determind where offers better rates..