I'm also located in Canada - 2hrs east of Ottawa. Reagents when stored properly last a while and I've been able to use my TF-Pro Salt kit for 3 seasons. Just purchased a refill kit during the 20% off sale last month. It's a bit pricey but so is a pool. I've yet to battle any water chemistry issues and pool has always been clear.

I do use more of the FAS/DPD Reagent and Powder as I like to pretend to be Dr. Emmett Brown some days, but these can be purchased from Amazon.ca when you're in a pinch and you don't have to pay extra shipping costs. I use Shippsy. They clear the package and bring in into the country for $6.99 and they can also ship it directly to your door for a reasonable charge.
This is the thread that describes the steps to get the kit to you in Canada.
Hey all, I wanted to document detailed steps for ordering items from TFTestkits.net into Canada using Shippsy to handle the cross-border stuff. This is a follow-up to these instructions so big thanks to @MostlyCanuck (I had never heard of Shippsy)! For cost, my TFTestkits.net order came to $200...
www.troublefreepool.com
It is indeed alot of $$$ for the kit considering our CAD, but for me it is well worth it as our swimming season is too short to be fighting water quality issues. You can always make the money, but you can't get back the time.
Enjoy the pool season