Most of the time, lost keys have to be replaced because there was only one set to begin with.  Too many times people have told me they only got one set of keys with the car and was going to get more made, someday.  You are just asking for it by not going straight to Walmart, or what ever you have locally, and getting copies made as soon as you buy the car.  Except for high security keys, you can get several copies made for less than ten dollars which is a whole lot cheaper than paying a locksmith to generate keys from scratch, especially if there are no codes available for your car.  Also, your time and frustration of being without your car has to count for something.

    Some dealerships will make another set of keys for you from the VIN (vehicle identification number) which is the long number and letters that can be seen through the bottom of the windshield on the driver's side.  The VIN is also located on your insurance card and car title which you will need as proof of ownership at the dealership when you pick up the keys.