Yup, I lost both my keys in a week on my Dodge truck (in the snow), and ended up having to tow the truck to the dealer to get one cut and programmed. That one had the remote in the key. It was $90 for the key, $15 to cut the key off the VIN, $25 for the programming, and $70 for the tow! $200 because I lost a key while shovelling snow. I got the two keys back when it thawed, and now I have 3.
Funny thing, I lost one about a month ago, and the other day I felt my knife drop out of my jacket pocket down the side of the Mustang console, and when I reached under the seat to grab it I found the Dodge key!
The chip is a transponder, and while it isn't too expensive in itself, it's the programming and cutting from a VIN that sucks. Note to self: always have a spare. If you lose the spare, get another BEFORE you lose the second one.
Sold: 2006 GT Premium Vert, 5 spd, Tungsten Grey
New toy: 2001 Porshe Boxster S