How well do the cubes keep though? And how do you tap them cleanly? I got the impression they're meant to be pierced by a fitting in a minilab, which will suck chems out as required.
And where (if you're an Australian) do you buy them? Vanbar seem to cost more than buying even small quantities from Ag and they're not clear at all on what it is they're actually selling (no manufacturer's item numbers, etc) so it's hard to tell if you have everything necessary.
One guy at one of my local labs is very helpful and was offering to let me buy bulk quantities of E-6 chems through him and his wholesaler. He did warn though that the pre-bleach keeps really really poorly and they'd found that out the hard way, watching their process go bad as quantities and therefore replenishment reduced. I don't have the factory's facilities to nitrogen-pack an open bottle, though I could use butane like I do with XTOL.