RE:RE:Naturevan is officially on Amazon U.S.A I don't yet know for sure, iscfa, but you may be comparing apples to oranges. It's certainly an important point that you bring up.
The best probiotics for a person can depend on the strain of bacteria, how many bacteria the supplement contains, and whether or not the product also includes prebiotics. Some research suggests that probiotics can help keep the gut healthy and may help relieve the symptoms of some health conditions.
First of all the products are different. On Amazon the product is Women's Probiotics while on the website the product is Probiotics Premium. Interestingly the Women's has 50 billion CFU's while the premium has 16 billion CFU's ....so by numbers alone the Women's product would appear better ...but that's only if the strain of bacteria is better.
CFU stands for Colony Forming Units. What this means is the number of alive and active microorganisms in one serving of a probiotic dietary supplement. These are typically measured in CFUs per gram or per milliliter. A colony refers to the individual colonies of bacteria, yeast or mold growing together.
Obviously, as you mentioned, the price points are very different. Until one knows more about the ingredients it's impossible to compare. It's a huge market so who knows what buyers of the products are making their decision on. As for price alone, 3x the Women's product price (180 capsules) is $111 CAD.
Cheers!
P.S. I don't see the Women's Probiotics found on Amazon as part of the product line on the Nature Van website.