07 Altima remote start?
 

I hope I'm posting this in the right area. Here's my question, I'm stationed over seas and I'm coming home for leave soon. Someone close to me just purchased an 07 Altima and I'm looking to get a remote start as a surprise for her. I've been searching online and I have not been able to come up with a lot. I called the dealership where she purchased the car and they want $495.00 for it. I was wondering if any one has any experience with remote starts and the new intelli key system. Would I be able to go else where for cheaper? such as Bestbuy? or maybe a specialty shop? And does any one know if this would void the warranty? Thank you in advance for any replies