If you're going to spend more than 5 days combined at Breck, Keystone, ABasin, Vail, and Beaver Creek, get a Epic Local season pass. They are about $500 and pay for themselves in 5 days, and cover all 5 mountains. I think Vail and Beaver have a blackout date on Valentine's Day, but you can hit any of the other mountains that day. You can buy them at the cheapest price in April 2014 for the 2015 season.
Awesome tip man. Even better because I just googled it and it looks like we can get an Epic Pass for $689 which also covers some of the Tahoe resorts - we were planning to kick the trip off by heading up there for 3-4 days with some friends who live in SF, two birds with one stone.