Ken's tour: We walked in and got two reservations right away in late October. At the entrance you have to pay $8/person fee and the tour is $20/person.
A tour guy takes on 10 people and walk to the valley. Walk/climb down three sets of steep stairs and the beautiful rock formations are all over you face.
We didn't have the luck to see any sun beams, but we are still very satisfied. The walk is short but you have to constantly stop for pictures. We spent in the valley around 1 hour and 45 minutes. The tour guy said summer is not good because of the crowds.
While the canyon is breathtaking it clearly being managed not with preservation in mind but rather profit. They squeeze the people in like cattle. The entire cavern is a. Giant single file line. The guide knew which camera setting were ideal which is great but seemed to know nothing beyond the basics about how the canyon was formed or the history of the area. It's a photo op not a hike.