I'm in the same boat only I got about 10 vacation days left so trying to burn a few on a vacation instead of just laying around the house for two weeks at Xmas time
I looked for lift/lodging combos but didn't have much luck.
We're also flying southwest, it's really the only way to go. Cheap flights and your board flies free, no baggage fees. And they do non-stop flights to DEN. I had some credits from a vacation we canceled earlier in the year so we just used those to pay for our airfare. Giggity.
Just like airfares, lodging prices go skyward after Dec. 18. so to get a really good price you'll have to go earlier. There were 1BR places for like $90/night in Frisco a few miles away, but if you've got a few friends to go with you you can probably find a place in Breck near one of the gondolas for under $150/night.
Last year in Park City we used VRBO.com to find a house/condo to rent and it worked out pretty well, so I went that route again this time and found a 2BR condo for $125/night. There is a cleaning fee on top of that, but for 4 of us for three nights, we are paying $130/person for the condo, or about $35/person/night.
If I was going with all bros, we'd save a bunch of money by piling 4 of us in to a Holiday Inn hotel room or something like that and save some scratch, but gotta class it up a little bit when wives/girlfriends are tagging along.
So we got airfare & lodging for about $350/person. I'll end up buying 2 lift tickets, the wife probably only one. Then food, beers, etc. A nice little extended weekend out west in the mountains probably run about $1300 between the two of us, but that takes care of our christmas presents to each other, and it's also the only vacation we've taken together this year so I think it's a pretty good deal.
If you end up out there at the same time (we'll be on the slopes 12/12 and 12/13, flying home 12/14) get in touch!