Where in SoCal?
Also, check out the for sale section on here before you spend $100 or so on just the replacement key without program from a dealership.
Factory Key Fob
I would highly recommend checking out the VIPER alarm/remote start or even a simliar lesser grade product. Heres the reason.. They have to program the key anyways to get it to start the car. So you'll have to pay an audio shop to program the ignition of the car. However you have a manual, so i am not sure if you can have the remote start function.
Nissan Fob - $80+Shipping + Programming
Aftermarket- $50-200 Installed