Hi Moxi. Living in Arizona I can say that I make my way there almost every two years. Yeah, Antelope Canyon is open, both the Lower and the Upper canyon. The fee you pay is for the right to enter the Navajo Nation's land, it's on Navajo reservation. Then you go in with a truck full of other people and spend an hour shooting. If you stay longer than an hour then you have to pay extra. The problem with the Antelope Canyon is that it's way too popular and everytime you want to take a shot there's going to be someone passing by and ruining your shot.
I much prefer to go to another Canyon, much less known, called Canyon X. It is a guided trip, the guide is a local photographer called Jackson Bridges (Google it) and he only takes photographers on that trip, no tourists. It's more expensive but you stay as long as you want or as long as you have the perfect light and there are no tourists around to ruin your shots.
Another place to visit is the Waterholes, a little South of Page. You do need a day permit (same Navajo Nation rules) but no other fees and you can stay as long as you want. However, it's several miles from where you park, although you travel on the bottom of the canyon.