Bring as much cash as you possibly can. I don't know how much you know about the blue dollar... but yeah. Bring thousands if you can. The larger the bill the better the rate you will get.
Also, the biggest city you stop in is likely the one you want to exchange money it. You'll here people calling out exchange rates on the street, don't exchange with them. You will very often receive fake bills that way. Go into a higher end shop and you can exchange there. If the rate is 14.6, they will probably give you 14.5 but at least your bills will be real. If you bring some 20's with you, you can use them in a pinch at the grocery store or for a taxi. Some restaurants and stuff will actually give you a better rate if you pay in USD.
Pay for first class bus tickets when you can. They are insanely nice and worth the $10 to $20 more if you're going to be on the bus more than 10 hours.
Cremoso cheese is awesome and cheap.
If you can, bring anything you would be down to sell with you. Your used gear will sell for the same price as new gear while you are there. Ask a ski shop if you can put up a flyer towards when you are leaving.
Everywhere I went the internet was crap and free wifi is very hard to find. Invest in sim cards with lots of data. The data will likely work better than any wifi you get. Depending on your phone, you may be able to tether.
Dulce De Leche is not breakfast! It is clearly a nation of confused individuals. But whatever, you may like them.
Media Lunes are delicious; I prefer them without sugar.
Rapanui makes the best chocolate. That Russian place is confused.
Bring hot sauce with you if it's something you enjoy. It doesn't exist there. Neither does peanut butter.