Maybe not a $100 a key...
I just received a "sentry" key blank that I bought on eBay for slightly less than $20. Of course, it doesn't have the "Lock, unlock buttons", but when the key is cut tomorrow, it should manually lock an unlock the doors and IF it has the ability to be programed, it will also work in the ignition. According to the manual, you can ONLY program these keys if you have both of the original keys. As to whether you can program another one of these keys with ONE of the original keys plus one of these sentry keys that has been programed is the $64 dollar question or is it the $100 question?