Although I don't know how much Taylor sells the chems/kits in Canada, those prices sound like the big bottles.
If you go to Doc's site you'll see that the large bottles are about $7 US and the small about $3 US. I tend to keep my testing chems in a cool, dark place (basement steps) and they last a while longer than the 1 year IMO.
I bought the larger size since I also own a pool and test PH and chlorine during the summer months as well.
Quite honestly, I don't test all the parameters that often, calcium every fill for the tub and in the pool once or twice a season; I test Alkalinity very infrequently and I also only test the CYA in the pool. If I did do all these tests all the time I probably would just buy a whole new kit every time I needed a bunch of reagents and add a small set of reagents for chlorine and PH.