Keys are not the first thing you would probably concider the price on. But they can be quite expensive if you have to buy one of the new transponder car keys.
Many remote keys are as much as $500.00 from a dealer and cost more if you need to program it into your car. I found a locksmith Brisbane selling keys from $45.00. These are some of the cheapest prices I have found yet for a transponder car key.
Some keys such as BMW are selling at $300.00 for a non remote and $500 for a remote key. They are not bad when you consider they come cut and programmed from the factory ready to start the car. A Hyundai I30 Blank was $450.00 not cut or programmed.
I would definitely shop around if you were looking to buy a new car key as there are some really big differences in prices.