Bolivia requires a VISA to enter, either overland or by plane, but you can get it upon entrance. It costs $135 (my info is from when I crossed from Peru in May 2011).
The reciprocity fees for Argentina and Chile are only charged when you enter Santiago or Ezeiza airports, and you ONLY have to pay once for the life of the passport.
I have never heard of an Iguazu day-trip visa. What I know is that Brazil requires Americans to get a visa in advance, which means go to a consulate outside of Brazil, fill out the necessary forms, it costs somewhere between $135-$150 (I never had to do it because I have dual citizenship and entered on my French passport).
Since you asked about using your DNI booklet, just so you know, foreigners are given a different sequence of numbers (I think starting with 99 or something like that) and they will know that you are not Argentine. Plus, my Argentine friend traveling to Bolivia didn't have his DNI booklet, but this special card that was either like a driver licence, or something to do with MERCOSUR so that he could travel without a passport/DNI.
If you travel overland to Chile or Argentina you don't pay the reciprocity fees. Or if you fly into a smaller airport somewhere else as well. GOod luck!