A friend of mine from Sg also mentioned that there are more people on Sundays and there is often a sale then too.
Its better to visit the China Square Central mall on a Sunday, because that's the time when there'll be extra tables set up by various sellers... in addition to the already existing toy shops in the mall. There you'll find all your Tokusatsu, Marvel heroes, Anime, WWE collectables etc. You can get them at a cheaper price if you visit the flea market (which is why you have to go on a Sunday). To go to the place, drop off at the
Chinatown train station.
There is also
LaTendo-- another shop selling the latest Anime + Tokusatsu stuffs (SHFs etc etc). The shop can be found inside the Funan DigitaLife Mall. To go to the place, drop off at
City Hall train station.
As what jacky has mentioned, there is the Takashimaya mall, but there are not much Toku stuffs there, unless you just wanna go sightseeing and see cheap Toku stuffs like the Rider Hero Series vinyl toys and some Power Rangers RPM toys. To go to the place, drop off at the
Orchard train station.