Unless countries have bilaterally deregulated, all J/C, F and Y base fares between any two destinations are standard to all carriers and filed with IATA, their trade association. Thus TG will have a published based fare that is the same as SQ and any other carrier flying that route, irrespective of the actual service provided. As noted, most TAs are able to get J and F at lower prices than the IATA reference fare, so few seldom pay this fare. Also, most routes in this region in J/C are generally heavily booked and often sold out. If TG can get the higher fare, why not post it. Unless they deliberately want to discount their fares to compete more aggressively, there is no point in altering this published reference fare.