That must be it. I incorporated my dad's company as a sole-proprietor and it was dirt cheap. I am guessing the process gets complicated when more than one founder is involved. Blood thirsty lawyers!
If you're in Canada, and you set up a sole proprietorship for your dad, then you didn't incorporate it. Corporations and sole proprietorships are mutually exclusive categories of companies. Setting up a sole proprietorship is as easy as going to a business kiosk and filling out some forms.
You're using the word "incorporate" incorrectly, which was my original point. To incorporate means to start a corporation. Therefore, registering a sole-proprietorship is, by definition, not incorporation.
The more general term is "register", which applies to the three forms of business: sole-proprietorships, partnerships, and corporations.
What you're thinking of is a business name registration. If you do business as your exact name, you don't need to register a name. If you make more than, $30k (I think), then you do need to register for a GST number.
I'm curious about that whole aspect of things. At this point, they must have it down to some sort of a formula. What kinds of variables are there? Stock, board of directors? They've got to have something of a cookie cutter by now...