Muskoka, there is only one daily AC flight YYZ-CDG (and one out of YUL), and to my knowledge, it's quite popular. Notice that the route's not part of the current seat sale.

Normally, you can get a fare of around $800-$900 by booking well in advance. The seats fill up quickly for the summer, but the fall shouldn't be a big problem. I went last October for $600+ taking advantage of the last seat sale.

I just find it odd that the lowest fare you're getting (and I'm assuming economy class here) is around $1500. If that's the case, I'd hold off on booking my seats until I had more certain knowledge about this fall's fares.

Tom