I have a breakdown of the resorts that I made for a ski club last year if you want it. I travelled and worked as a ski guide for 6 years and know the ski areas quite well. It gives a general idea of the resorts in Chile and Argentina, places to stay and what to expect. PM me and I'll send it your way.
You might consider head to argentina ? - usually better value for money
These are some common sense stuff that'll help keep it cheap
-Learn some Spanish before you go - It opens a lot of doors
-if you're going for a short trip say less then a month avoid moving around a lot
-take the night bus to place so you don't have to pay for bed
-The International rule-> buy your food prior to going up to the ski resort
-Bring your ski touring gear. Buy tickets only when there's new snow at the resorts.
-Travel on the local bus not private transfers
-If your a student bring your ID for discounts
-Bank Machines-Find the one that gives the most cash. Otherwise you'll get hit with bank charges
-Bring a Tent and sleeping bag - Saved me bunch in Las Lenas for the first couple years when I was dirt bagging it.
-Sell your old/extra ski gear
-Find a group and buy as a group - You can get discounts if you organize things for others travelers that can't be asked