I'm going to be in Singapore for a few weeks, and I'm already picking up one of these powerbanks for another bushwalk forum member. The battery pack is quite a bit cheaper in Singapore, direct from the Xiaomi store than it is from retailers here in Australia. http://www.mi.com/sg/mipowerbank/
I will be able to bring another one back with me, so if anyone else wants me to get one, shoot me a PM, and I'll get you one at cost - it should be around max $32/33 once I factor in the shipping (they only ship these to Singapore), and the exchange rate.
These currently go for around $50-$60 locally, although some retailers do occasionally discount to $40.
Reviews and critisms from DanShell's thread here: viewtopic.php?f=21&t=19706
The only catch is I will be back in mid/late June, and you have to pick it up from inner eastern burbs in Melbourne, and I can't bring many back as I have to bring them in carry on luggage. And the other issue will be that there is no local warranty obviously - the warranty is for 6 months in Singapore http://www.mi.com/sg/service/. But from reviews and teardowns of this charger, these chargers do seem to be good quality.