Can I bring a new stroller back from the states in a box on the plan?

I am going down to the states and was looking at getting a new stroller...can that be transported on the plane back to Canada? It weighs 36.95lbs and is 25.0 x 45.5 x 42.0...would it be oversized? Does it have to be in a "luggage" bag? If it is oversized than it will only cost $75, if I have to ship it then I will have to pay $140.