I agree with all the other posts, but living in SF, I've learned to love Sierra cement.

One semi-budget ski-in/out accommodation at Heavenly where I've stayed and which I've found pretty reasonable is the Concept Sierra condo complex--they're rented by owners--on the CA side. Not the most luxe of condos, but the units I've rented have been more than respectable, and they turn up on the Craigslist vacation home listings in the bay area (so you deal with owners--maybe not as easily booked as you wanted, but you have to give on something here). Full disclosure--not necessarily ski-in/out to your door--there's usually a little walking across a parking lot--but no driving and 5 min walk max.