therealsassyor pinch a pair of rentals.
BumpzNtreesActually this might even be better advice. Just walk into any rental place at the mtn and say "i forgot to get poles"
baitgo outside the rental loge at any hill and snag a gaper'S sticks.
Yeah...unless you're a complete jackass, don't do any of these things. Stealing ski gear, no matter how cheap or inconsequential, is a really scummy thing to do. You could go to a shop and ask if they have any old or mismatched poles they'd be happy to give away or sell for cheap, or go dumpster diving until you found something that works if you really can't spare the money for a pair of poles.
My opinion is poles don't really matter as long as they're the right length, or you're really into touring and want something adjustable for the way up.