You can catch a $12 (round trip) shuttle between Breck and Vail. I don't think the shuttle stops in Frisco, but you could call 970-496-4FUN and ask. You can also catch a shuttle from Keystone to Vail, but that's further away.
You can get to Breck, or anywhere else in Summit County, for free by using the Summit Stage. From Frisco, it will take you approximately 1 hr to reach Breck by bus.
Thanks for the link, Lisa. Only thing is based on the Vail express you wouldn't even be skiing until probably close to 10 a.m. and you'd have to be bus-ready pretty early (no time to even buy a pin unless you quit early!).
I'm going to have to comandeer the vehicle for the day.....