amtrak only goes to vancouver, and then there is a panoramic train or something of the sort that goes from vancouver to whistler, however, to do that last stretch is like $100+ each way, so its wicked expensive. BUT, the train, to my knowledge, doesnt run in the winter (at least not yet) so there is only greyhound (which is cheap).
i usually take the train from seattle, which is like $20 each way, then like another $15 each way to whistler. From northern california, it'll be around mid $60s to mid $70s or more each way to vancouver. Its cheaper if youre a student or have an ISIC card (but not significantly).
not so, I almost got kicked off amtrak in the middle of Nebraska on the way to denver for being drunk, they called the cops to meet us at the next stop... and the bastard conductor poured out my Black Velvet.