Last year, there was a long discussion of sources for keys. I have a 2007 Murano and was charged over $100 for a key and $60 for programming it, and was so upset that I wrote a letter of complaint to the dealership and got apartial refund.
I later went to ACE Hardware and they checked the key, then said they could replace, cut and program it for about $70. I recently learned more about this.
There is a hitch in the ACE Hardware route for replacement keys. This summer I lost one of the three keys I had, and in going to ACE for a replacement I learned that a special computer programmer is required to mate the key to the car, and not all ACE stores have it. Before you assume they can program a key, check with the store and be patient while they figure out whether they have the computer tool.
I found that the store in Fort Collins CO (pop. about 130K) does not have it. I haven't been able to confirm whether the Denver stores do.
It also appears that they need at least one functional key from which to program. I'm still trying to get that sorted out - some of them said two keys, some said one.
Just wanted to do my best to issue this note of caution.
I'm absolutely NOT going back to my local Nissan dealer, as I've found that they are invariably at least twice as expensive as any other place, and it's a 30-minute drive to get there from where I live. (It's even cheaper to get my wife's BMW worked on by an independent shop.) I'll live without the extra key until I find a less expensive option.
Incidentally - a Google search will reveal numerous sites where the unprogrammed blank key is available for less than $20. That doesn't cover the key cutting or programming, but if a dealership will program the key, you'd still come out way ahead.
Here are two sites:
There is also Ebay, where keys are available in the $6-$10 range plus shipping.