[dfalconer]

Rob,
Same thing happened to me back in July. No used replacements were available in the used parts inventory anywhere in Ontario. Ended up ordering a new one from dealer. Took 3 days to get in from Chrysler's Montreal warehouse at $480 Cdn (ouch!).
My advice in this order:
1) See if an alloy wheel repair specialist can repair (dealer will probably say it can't be done)
2) check for a used wheel in your region
3) order one off ebay for ASAP delivery - there are a number of current auctions
4) order a new one from the dealer if you are prepared to part with the cash.
By the way, a wheel specialist straightened the wheel and repaired the crack and looks good as new. I'll soon buy 3 more off ebay for my snow tires.
Don