I used to get the Horley's Carbless Crunch but eventually the piles of maltitol or sorbitol or whichever sugar alcohol they have in them got the best of my digestive system.
I'm strictly whey protein isolate for protein supps now.
I'm surprised the supermarket is cheaper - they had the odd special on the other carbless ones, when they were cheaper than anywhere, but I haven't seen that on the Crunch ones. $43.99/doz for the ones I got or $3.67 per bar - they were always well over $4 at the supermarket.