Unless you are in souther california, I dont think anyone is going to be able to help you with that, as keys are pretty rare for BMs. Try this source, www.replacementlaptopkeys.com,
they always have the dell laptop key replacement i need in stock, and even if dell will replace it under warranty, its sure beats sending out your laptop for a week.
You won't have to send the notebook for repair - they'll send you a keyboard, which installs in ten minutes. Chances are they won't even ask for the original back (which means you have a spare set of keys by default). Beats paying for a key or keys when you're under warranty!