Yes, it's expensive but it's a very labour intensive tourist attraction. Two people at the bottom of the tower checked our harness equipment several times (including testing your shoes to make sure they're not loose) and then a different two people rechecked at the top of the tower. You're attached to the tower in two places so it's quite safe.
There were only 6 people in our group and you're out there for 30 minutes. The fee includes a dvd of your walk as well as a ticket which allows you to return for the "regular" trip up the CN tower within the next 3 days. Because we were a family of four, they gave us one CD with the photos of our walk without a cost and then we all copied it on our own following the trip. thank you!!
You are NOT clinging to the side of the tower like Rick Mercer and Jann Arden! The grid you walk on is as wide as a Toronto sidewalk. There's plenty of room and my sister, who only went on the trip because she said "I'll never live it down if I don't", went from barely being able to stick her toe out over the edge, to leaning back in the harness over the edge by the end of the walk with a big smile on her face.
They give you the opportunity to approach the edge so many times that the amygdala in your brain learns it is quite safe by the end of the trip and stops freaking out.
It was beautiful up there! I kept thinking I'd love to take my lunch and just sit there in the quiet with the wind, looking out over the islands... I just wish I could afford to return repeatedly!
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC.