UW isn't private, a good chunk of the tuition is subsidized by the Canadian government for all Canadian citizens. On top of that undergraduate student loan interest is also paid while you are studying at the school.
UW may not be private but the pricing is based on supply/demand not costs. For example, a first year student enrolled in Math pays half as much as a first year student enrolled in CS. They both take exactly the same courses in the same rooms at the same times with the same professors.
Engineering and CS students subsidize the rest of the school in order to improve the university's rankings. We're just cash cows to them.
Their co-op program was, and continues to be, pretty awesome. This, IMHO, is what first got the great students to go there.
With university cost only increasing its nice to know you'll be able to pay your way due to co-op.