As Jamesdelux said, the best deal if you are going to ski 10 days is the perfect 10 ticket (actually, it is still cheaper if you are going to ski more than 7 days even if you toss the extra tickets). You can also buy advance tickets on the vail website at a nominal discount- you save between 10 and 15% from the ticket window price, even for multiday passes. The best deals, however, require you to be in Colorado in September and sign up for either a Colorado Card or a Colorado Pass. The card is free, and entitles you to steep discounts at all of the Vail resorts plus A-Basin (and 6 same-priced discounts on each card for a friend). The pass is an unlimited season pass at Keystone, Breck, and A-Basin, plus 10 days at Vail or Beaver Creek (excluding some days between Christmas and New Years) for (believe it or not)$279.00. The problem is that you can only get them in person- no mail, phone, or web sales. They are available around the Front Range in September (this year through Nov.)- if you are out this way at that time, it is definitely worth buying- I'll be skiing for about $11.00/ day this season.