I know most of you make your own cakes as I do too but does anyone use ready made cakes from a supplier? Just the plain cake itself and you decorate it. Was wondering if anyone has experience with this.

There are several wholesale bakeries that ship frozen cake layers.
Some, if not all, have minimum orders which may be 40 cases or 200 cases.
(you'll normally get small unit discounts for breakpoints over every additional 200 cases that you order.)

If you're looking for a facility to order from, I believe the "go to" place in Canada is McCall's:
http://www.mccalls.ca/

This is exactly what I was looking for! Thank you so much for this information and link, you are very helpful.