I have done several cheap ski trips: Jackson Hole (7 days, transportation, lodging, ski tickets, food for about $450), Austria (significantly more, but still under $100 per day including airfare, and am headed to Colorado this winter. We are staying in Silverthorne, which is about 10 minutes from Keystone, 20 each from Breckenridge and Copper, and about 15 from Arapahoe Basin. I would recommend staying there (we got a $66 a night rate for the first week in January off Priceline), and driving/taking the bus to the resorts.

Arapahoe Basin will be your cheapest option for skiing, make sure you get a Colorado Gems card to save more. PM me for info on how we do it.

I am currently planning a trip to Japan and we intend to also do it for under $100 per day and should be successful.