Not the cheapest ever (as Mushtato has offered these for $25.95 in the past), however I think it is still a pretty good price at $28.85 for a genuine product, local stock, free shipping and as an added bonus, you get the eBay buyer protection.
FYI, Mushtato's website lists these at $32.95 (http://www.mushtato.com.au/genuine-xiaomi-portable-mi-powerb…)
bought this the other day, $1.30 cheaper (aus stock and supposedly genuine)
http://www.ebay.com.au/itm/100-genuine-XIAOMI-external-USB-b…?