hey shazam,
I'm very familiar with the toy scene in Singapore and I'd recommend you try to squeeze in a Sunday for Singapore when you stopover there.
Every Sunday at China Square Central (somewhere in Chinatown) there is a gathering of toy sellers much like what we have here in Perth (Nexus) just that the amount of stuff (bots) would be heaps
heaps more.
Sellers will be trying to out do each other to clear off their stock so you'd need to bargain. Most times for current items, the rate is actually less than the yen price (for japanese toys) stated on the boxes.
Check out my blog (
http://dat70sdude.blogspot.com/) as I've done an extensive coverage (i think!) of the places you can head to to shop for bots in Singapore.
Good luck! :)