If you go to the SuperMax website, you may find they still offer it - one or two tubes, cant remember - along with 750 Blue Diamond blades and a shavette (which should be thrown away immediately) for £7.50. Hunt more and they may sell you cream alone.
A quick look on ebay has a guy selling six tubes for £5.50 plus postage (I'm set to being in the US so I don't know the postage). Even at £12 all in, that's £2 a tube which is a good price, surely? You don't want six - sell 'em on or keep 'em. I was given a tube yesterday and told the giver, "You can never have enough SuperMax cream".
SuperMax cream with a Blue Diamond blade with your favourite razor and brush gets pretty close to heaven!
Macca Root shave cream from Bodyshop is another excellent but cheap shave cream if you wait for the right offer.