PakLite Sto-Way in all sizes are on sale at Peter's of Kensington. Only Grey colour is available.
These are collapsible so great for storing when not used. Also an option if you're still looking for a two-wheel luggage which is rare nowadays.
They're around $130+ elsewhere.
Also available on their ebay, to get 1% cashrewards. Unfortunately since they're under Travel category, PICK5 is not applicable.
Free C&C is available (Sydney only), or delivery is $7 to Sydney. Postage rates here.
Interesting concept. However the smallest is a bit heavy as cabin baggage at 2.8kg. Plenty of 1.7 and 1.8 around. Very important for me using AirAsias 7kg free cabin baggage allowance :)