Yep, the foam itself is "Clima Foam" XPS "Knauf" from QLD. http://www.knaufinsulation.com.au/en-au/insulation/climafoam-xps-board.aspx
NB that the rated density/compressive-strength is 300kpa, which exceeds that successfully used by "Swans Crossing" and "Broughton Vale" over 20 years ago.
(higher density = higher weight per sheet for a given dimension).
NB also that while the foam will work to give a quick "flat tabletop" surface to work with,
it is simply not capable of supporting any truly-reliable and "road ready" high-accuracy alignment or module-locking system in and of itself.
With suitable end-plates and a 4x4 "ladder frame" qublelok frame as was fully explored at the 2013 Aust NG Convention, this foam could be quite useful.
However, you're a long way from eliminating Qubelok altogether, esp if the layout in question requires any more than 1x module...
Aim to Improve,
PS Capral and a decent hacksaw rip all over Bunnings for aluminium tubing price. As a live-fire comparison, my last layout project
(2x scenic'd modules + train-turntable staging module + drop-leaf traverser + legs) worth of aluminium and joiners priced out at well over $500 via Bunnings "Connect-It" range
(as supplied by MetalMate/RCR http://www.rcr.com.au/metalmate/metal-mate-diy-connect-it-system/
In comparison, raw Qubelok tube + joiners from Capral,
+ a case of beer and a day at a local sympathetic metalworker/model RRer's place
(I piggybacked on their already-scheduled layout module-aluminium source+cutting day)
= well-under half that price...