It doesn't have to cost anything. You can take a tent with you and camp at the bottom but I believe you need to sign up with the park so they know you are there in case you have issues. You can ride a mule down there for $143. There is also lodging down there but that requires reservations months in advance. Good luck and be safe. Always let somebody know that you are going down there even if not all the way. That way if you don't return they will send a search party. It's very safe if you are careful and don't do crazy things.
You can walk down for free. But remember hiking down is optional hiking back out is mandatory. And its not a hike for the faint of heart or those not in good shape. People die in the canyon every year because they decide to hike to the bottom when they are obviously unprepared. To stay at the bottom overnight you have to have a permit, which can be hard to get, and also pay the fee. Permits range in price Depending on time of stay and location. Say the corridor trails vs Supai etc
You just pay $30 (for a private car) as an entry fee for 7 days.
I hiked down the Grand Canyon in October. It was a fantastic trip. Took about 8 hours to hike down and 7 to hike out. Stayed at the Phantom Ranch one night and that was a great stay. Must book early because it fills up fast.
It's not done by the park service. We have drines. I doubt a local Navajo would do this. Wait until summer
This is not an easy thing to do. I think you need permision and accommodation at the bottom. It can be dangerous.Check with the National Park.
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