Hello OP,
A couple of things...
I'm an American and I had to go through hoops to get a Brazilian visa. I'm not whether you will need one, too.
But Chile has its own $100 US fee. The $100 fee is good until your passport expires.
I do not if you are in transit if you have to pay it. So that's something that someone else can tell you.....having to pay an additional amount of $$.
David