So I asked around to see if anyone knows where I can buy Javelins in Toronto and the best answer isn't even in Toronto. The company has Toronto in the name, but its located in Markham.
Sports Equipment of Toronto Ltd.
250 Telson Road
Ontario L3R 1E6
I warn you in advance however that javelins can be a tad expensive. (Which makes sense why so few people get into the sport.) The prices listed at sportsequipmentoftoronto.com/shop/category.aspx?catid=223 range from $1,115 to a mere $50.
So yes, you could get into the sport for a mere $50... but lets be realistic. Do you really want to throw ONE javelin and then have to go pick it up? No. You're going to want at least 4 or 5 javelins that you can throw, and then go pick them all up at once.
So if you want to get into it as a sport you have to be thinking of spending $200 to $6,000, plus you may want to get books about throwing technique, a coach who can teach you how to run and throw properly, or even special gloves or track and field shoes.
But hey, extra equipment is pretty standard with almost any serious sport.