Replying to US road trip, PC and Breck

So me and a mate are thinking about getting the epic pass and hitting park city then breck/keystone over 4 or 5 weeks around Xmas and the new year. However, looking around, accommodation in and around the resorts looks pricey. Is it cheaper to stay in SLC or some other bigger town/city and travel in or is there some other alternative we've just missed. Also, do you think its cheaper to use buses to get around (including going from Utah to Colorado) or buying a real cheap, used car for the time? Any advice on this or general ways to keep costs down would be awesome.
Safe