I've not found any cheaper source and as I'm in also in USA, I've also ordered. The 10 lb/4.5 kg bag
is USD30+12 shipping, which for cheese making is a ridiculous amount as even at 1 lb, i suspect it will be a life time's amount
In case Ben's link expires, the ebay vendor also has an online store
and I suspect he/she will post this product regularly.
linuxboy, my understanding is that similar to NaCl brine, a 30% solution actually means 30% of the final weight is CaCl2. So for example, 0.3 kg + 1 kg water will weigh 1.3 kg and the solution is 0.3/1.3 = 23% CaCl2. At least that's the method I wrote on this webpage
which was based on this article
. Please correct me if wrong.