To be completely safe, I just buy PG/VG from Shoppers. $5for a 250ml of VG and $7 for a 500ml of PG. They always have VG in stock and can order PG in within a day or two.
I could save a few bucks, but I only use 2-3l/year so I don't bother.
I could save a few bucks, but I only use 2-3l/year so I don't bother.